Microsoft Knowledge Base Article 917484 contains the following summary and introduction:

SUMMARY

This article describes ways to troubleshoot the following common issues that may cause Microsoft Systems Management Server 2003 distribution point site-to-site connectivity failures:

The SMS computer account or SMS service account does not have local administrative rights on the distribution point server
Network issues
The distribution point share does not exist

INTRODUCTION

Consider the following scenario. You install a System Management Server (SMS) 2003 or SMS 2.0 distribution point. Then, you try to add or update a package on the distribution point share from the SMS console. However, in this scenario, the package may not be added or updated.

Additionally, the Distmgr.log file may show error messages that resemble the following messages:

Start adding package to server Servername \["Display=\\DPServer\"\]MSWNET:\["SMS_SITE=SiteCode"\]\\DPServer\...
SMS_DISTRIBUTION_MANAGER Attempting to add or update a package on a distribution point.
SMS_DISTRIBUTION_MANAGER

Cannot establish connection to \["Display=\\DPServer\"\]MSWNET:\["SMS_SITE=SiteCode"\]\\DPServer\ SMS_DISTRIBUTION_MANAGER Error occurred.
SMS_DISTRIBUTION_MANAGER Performing error cleanup prior to returning.
SMS_DISTRIBUTION_MANAGER

SMS Site System Status Summarizer still cannot access storage object "\\server\share$ <file://\\server\share$>" on site system "\\server\share$ <file://\\server\share$>".
The operating system reported error 2147942405: Access is denied.