Hi Tom,
Yep - that recent projects list on CaseComplete's start page is definitely tied to some information in a settings file, located in the specific user's AppData folder. In addition to the recent projects list, the file stores things like customized window sizes, what dictionary language you're using, auto-save settings, etc.
I'm not sure why the recent projects list would have changed, but it could be tied to the user name (since the file is stored specifically per user). If you're using roaming user profiles or the analyst changed user names or anything, that could explain the list being cleared.
Thanks,
Jason