Files hosted on a Windows Home Server (WHS), latest boxee running on Windows 7 64-bit. Scanning the SMB shares (i.e. media source listed as: smb://SERVER/Movies) from the WHS system gives inconsistent results, but 90% of the time returns with two or three files found when 30+ exist on the share, all MKVs, and all playable via VLC and Sage HD200 (accessing via the same shares). When it does find the files, it will later "un-find" them.
Note that the connection is all via wired connections through a gigabit switch. No other hosts on the network appear to be experiencing any connectivity issues.