I recently migrated from WSS 3.0 to SharePoint Foundation 2010 without any website-breaking changes. The only issue I've run into so far is that the URL for two Discussion Board Web Parts on the SharePoint home page have incorrect links.
The two Web Parts are essentially stock Discussion Board Web Parts added to the home page. On the old SharePoint site (running on WSS 3.0), each list item had a url similar to:
http://192.168.4.223/Lists/Team%20Discussion/Flat.aspx?RootFolder=%2fLists%2fTeam%20Discussion%2fSchedule&FolderCTID=0x01200200E8BF3AE7AA1C7548B1DEE2CA1003E22F
Clicking on the item in the Web Part would successfully take you to appropriate discussion.
On SharePoint Foundation 2010, after the migration, the links are as follows:
http://192.168.4.223/default.aspx?RootFolder=%2FLists%2FTeam%20Discussion%2FSchedule&FolderCTID=0x01200200E8BF3AE7AA1C7548B1DEE2CA1003E22F&View={41E4E9EC-FE4D-481C-A512-5971C2E252EF}
Clicking the link takes you back to the home page and the Web Part now shows
There are no items to show in this view of the "Bulletin Board" discussion board. To add a new item, click "Add new discussion".
instead of taking you to the discussion board.
However, if I go to the "Bulletin Board" from the Quick Launch bar and select that same topic, the link is
http://192.168.4.223/Lists/Team%20Discussion/Flat.aspx?RootFolder=%2FLists%2FTeam%20Discussion%2FSchedule&FolderCTID=0x01200200E8BF3AE7AA1C7548B1DEE2CA1003E22F
which, if you look closely, is exactly the link as on WSS 3.0.
With all that said, is there any way to fix the links for those Web Parts such that users can click on the item instead of having to go through Quick Launch?