Hi,
If we only delete list from Registry, these lists won't show in Recent Projects list.
To make VS to record the old project again, we can delete your solution file too (C:\Documents and Settings\YourUserName\My Documents\Visual Studio 2005\Projects\WebSiteSoultion).
Note: The path above is by default. You can find it basing on your setting.
If we do so, VS will create new solution file for your project (Prompt dialog window to ask you where to save this new .sln file) and record it in Registry.
I look forward to receiving your test results.