In my last column, I asked for feedback about Windows NT Server 4.0, Terminal Server Edition (TSE) Service Pack 6 (SP6). Many thanks to all who responded with stories about how it's working (or not). I’ve included excerpts from some responses below to give you an idea about SP6's reception. Some of you are running SP6 without any problems and others of you are running it with problems you can resolve:

"I've run SP6 on six servers for about a month now. I heard reports of problems, but I couldn't get any specifics. I decided to install SP6 after I didn't see anything go wrong in the lab. So far, I haven't had any problems that I can trace to the service pack."

"I'm running TSE SP6 on a Compaq Proliant 1850r and haven't encountered any problems. I also know of several companies whose systems have been much more stable since they went to SP6."

"We installed TSE SP6 on one of our Citrix terminal servers, and it crashed the first time we booted it. After some investigation, we discovered that the Compaq driver for our server's network adapter card has a bug. The network adapter card is a Compaq NC3131 Fast Ethernet 10/100, which came standard with our Compaq Proliant 6400 server. You must replace this driver with a newer, fixed version before you upgrade to TSE SP6. Fortunately, the problem device is a PCI network adapter card, so we could take the card out, boot the server successfully, replace the file with the newer version, replace the card, and boot up to be back in business. The fix would've been uglier if the driver had been for a device other than the network adapter card."

But not all the stories have happy endings:

"I recently deployed TSE and Citrix MetaFrame with SP6 for a major insurance and travel company, using 20 terminal servers to serve a desktop to Wyse terminals. The company relies on a travel reservation application that runs in an NT Virtual DOS Machine (NTVDM) and a companion product that runs in separate memory space. When the core application launches, it spawns an NTVDM at start-up, and the companion product spawns a second NTVDM when it launches. These two pieces must be able to communicate. When the reservation application loads on a server with TSE SP6, the application runs from the console without problems. However, if you launch the application through a Citrix ICA connection, the companion application fails to run and returns a resource error message saying that the host session is already in use. Apparently, SP4 and SP5 for TSE address this NTVDM communication error, but when you install SP6, the application no longer functions as a published ICA application or as part of a published desktop to a thin client. Microsoft is supposedly working with the vendor on a fix for the problem. In the meantime, the company recommends that you revert to SP5 if possible."

"We installed TSE SP6 and MetaFrame SP1 on the same day—big mistake! So much for maximizing a small window of downtime to apply patches. Soon thereafter, we encountered the ICA Browser problem, which hangs or disconnects all ICA connections. To correct the problem, you have to power off the server. After digging and posting messages looking for help, we turned to Citrix. A Citrix technician offered us utilities we could run the next time the server died to gather information for Citrix to analyze. Alternatively, we could reboot the server daily to avoid the problem altogether. Because our company's not a Citrix lab, we chose to reboot daily."

Note: Microsoft addressed the ICA Browser problem in article Q269214. You can download the hotfix from the Microsoft Web site.

"I consult for a bank that a year ago implemented an NT 4.0 TSE and MetaFrame 1.8 environment for remote access without major problems. Recently, we upgraded from SP5 to SP6, and shortly thereafter started experiencing severe and repeated STOP 0x000000082 dumps. As a Premier Microsoft Customer, we received dump analysis support that pointed to a fault in the driver Multiple Uniform Naming Convention (UNC) Provider (mup.sys) when mapping DFS drives. We use DFS on the LAN without problems, and we have used TSE from the beginning, but on a smaller scale than now. Unfortunately, shortly after the SP6 update, we realized that more and more users' logon scripts mapped their shared folders through DFS. Therefore, we can't yet put the blame only on SP6. The mup.sys weakness, when put to stress with more sessions that request a DFS drive, might indicate a generic TSE weakness with mup and redirector services. Microsoft is investigating the problem, and we hope to get a fix soon."

Note: The following comments refer to SP6 for TSE, which Microsoft released in May 2000; it's 128-bit. According to Microsoft, there's neither an SP6a nor plans to release one. The SP6 and SP6a dichotomy relates to SP6 for NT 4.0, which, as you know, you can’t install on TSE.

"The people who aren't using SP6a for TSE are missing an important update that corrects a lot of nagging flaws and buggy behavior. I have used the service pack since it first came out on a 4.0-TSE installation with no problems over a three-state frame-relay WAN with an NT 4.0 file and print services server providing PDC, Proxy 2.0 (with SP1), IDSL, Integrated Services Digital Network (ISDN), RAS, backup WINS, and DHCP. The service pack specifically fixes a major 16-bit application instability that built to a serious memory leak condition over several days. I don't know how SP6a criticism got started, but it's nonsense. The real bad boy is SP6, which Microsoft never should have released last November. SP6a-TSE (128-bit, of course) is a stable and important upgrade that almost everyone should be using now."

"I have applied SP6a (128-bit) on at least six terminal servers running MetaFrame 1.8 and have experienced no adverse effects. In fact, the service pack corrected a condition in which our terminal server would "lose" certain directory permissions on users' profiles after a reboot."

Because they're concerned about problems, some users will continue to play it safe:

"We have two production TSE-MetaFrame 1.8 systems that provide remote access to department services to more than 800 clients. My concern about SP6 is the ICA Browser problem. Most of my MetaFrame clients are dial-up users, so if the ICA Browser acts up, users have no way to access the system. I can't tolerate such problems because most of my dial-up clients work after hours, when dial-up is the departmental remote access method. My Citrix representative has advised me NOT to install SP6."

And some will play it VERY safe:

"I have NOT installed SP6 on any of the production terminal servers I run. I'm wary of Microsoft service packs and continue to use SP4 with some success."

There you have it, folks. I'll continue to assess the situation.