For the past year or so, I've been pondering methods for writing addendums to my reviews of software products, hardware, and services. The problem is that we live in an interconnected world, and everyone expects to find reviews of new products on their favorite Web sites as soon as possible. In many cases, I'm able to work with companies such as Dell, Lenovo/ThinkPad, and Microsoft to ensure that I have early access to products so that my reviews can be timely but also benefit from actual real-world experience. In other cases—Apple is a typical example—the companies involved are secretive about new products, or perhaps I'm just not on those companies' "A list" of reviewers. So, there are occasions when I don't find out about a product until it's about to be released, or—worst case—until it's actually available on the street. Regardless of how or when I acquire products for review, however, I face other concerns. If I spend a few weeks with a new Apple iMac, a digital camera, or a laptop, and I experience no problems at all, it's to be expected that my review would be positive. But fairly often, problems begin to crop up with these products over time. And although I haven't settled on a method for recording such problems, they've often accumulated to the point at which I wish I could change an existing review to reflect the problems I've experienced. I think of these changes, or addendums, as my response to problems that have occurred "28 Days Later," in honor of the movie of the same name. In that film, a virus appears to wipe out most of humanity, destroying society and forcing the few healthy remaining humans to fight for their survival. That's pretty much how I feel after a review goes bad.

Let me give you a few examples. Recently, I reviewed Apple's stunning iMac Core Duo here in Connected Home Express. I described the machine as "a winner ... with legs for the future," and I highly recommended it, especially for people who don't mind living on the edge (considering some software incompatibilities with some Mac OS X software). In the weeks since writing that review, I've turned to the iMac as my main email and Web machine, and I've spent a considerable amount of time working with its digital media features. I even reformatted my iPods so I could use them natively on the new iMac.

Somewhat predictably, I've run into a number of problems. Surprisingly, many of these problems have forced me to hard-reboot the machine (by holding down the power button until the device shuts down, then turning it back on). This is something that I've never had to do with previous Apple machines, and I find it disturbing. The Finder, OS X's shell (and Windows Explorer equivalent), crashes fairly regularly and can't be resuscitated. My iPod shuffle refuses to eject and then lingers in iTunes as a weird pseudo-playlist, and the iMac squawks when I remove the device manually. The iMac's three USB 2.0 ports are woefully inadequate—I need at least six, but eight or more would be better—and the Belkin USB hub I often use refuses to let attached devices appear in the Finder. I purchased a song from iTunes, and it won't download successfully despite repeated tries. Finally, 2 days ago, Apple Mail started crashing incessantly, for most of a day. I'm not sure what fixed it, but when I tested it for the umpteenth time late that day, it started working again. Now I'm not sure that I trust it.

Here's an even worse example: In October 2004, I reviewed HP's Media Center Extender on the SuperSite for Windows and awarded the product four stars out of five, noting that it was "an excellent solution for enjoying your digital media content from anywhere in the house, especially if you can connect the two via wired networking." That statement was true during the month-long testing period. But since then, I've tried to use the Extender, and an almost identical Linksys model, as my primary TV interface, and I've given up time and time again.

The problem is that the Media Center Extenders perform horribly over wireless networks, don't support all the features or even media formats that a true Media Center PC supports, and have never been upgraded as promised with new functionality. Protected content, such as that from HBO or Cinemax, refuses to play over the Extenders, and viewing rented movies from services such as MovieLink or CinemaNow is a nightmare. If I was reviewing this device now, I'd award it two stars out of five. I've wanted to toss it out the window more times than I can count.

So what's the moral of this story? I'm not sure. Like any tech reviewer, I try to get it right the first time because I know people are relying on me to make expensive and crucial decisions about consumer electronics and computing products. I have no reason to give products an artificially high rating, and plenty of reasons not to. But I'm as human as the next guy, and I can make mistakes. What I'd like is the ability to go back and fix things at a later date when necessary or, if possible, even confirm what I've previously written.

As for that iMac, I still like it a lot, and coincidentally, Apple just released OS X 10.4.5, which addresses a few Intel-specific Mac problems. But I stand by the notion that it's not ready for mainstream computer users. I'm sure Apple will fix any remaining problems. But I wish the machine was a slam dunk, and it's not. And I figured that out much sooner than the expected 28 days.