Yes, it is a common problem, and Microsoft **STILL** hasn't learned how to
handle (potential) remote resources/locators.

The problem is that one or more of your projects in the MRU list is located on
a remote resource.  The process of validating that remote resource can lead to
delays, which results in the IDE being slow to open.

Solution:  Erase the MRU list.  You can do this by changing the MRU # through
tools/options to 0 (or 1, whatever minimum it allows), closing, and reopening
VS.NET, then setting the MRU # back to what you want.  Note:  the problem will
reappear if you open the remote project in the future.

Note to Microsoft (or anyone that performs validation of potential remote
resources):  PERFORM VALIDATION IN A SEPARATE (BACKGROUND) THREAD -- DO NOT
BLOCK THE PRIMARY (UI) THREAD FOR VALIDATION.