First off, thank you to everyone who has attempted to help thus far.
I think the problem isn't being clearly explained. The issue is that the "My Documents" folder is missing from the "My Computer" window for all limited user accounts, i.e. if Bob is a limited user, when he logs onto his account and goes to My Computer, "My Documents" is NOT shown. XP only shows the "Shared Documents" folder.
For some reason, XP is hiding Bob's "My Documents" folder from him in "My Computer." The link from the desktp, start menu, etc. all work fine, and Bob has complete access to his files, but the folder is simply not being shown in MC. Furthermore, the option to show "Files Stored on This Computer" is missing in TweakUI for Bob.