Actually, I don't think it has anything to do with the number of files in the dir. I can run off Windows SMB shares all day long....but using Samba 2.2.7a on my Gentoo box does not work at all. FYI, my Gentoo box has Samba setup as a PDC and works perfectly (roaming profiles, SMB print server and all) for all of my Wintendo boxen as well as my Turtle Beach Audiotron. Yes, it even works on boxes that are not joined to the domain....so....technically it should work unless there is a bug in the SMB implementation in XBMP. My Xbox doesn't lock up....it just simply shows nothing at all...but I can still step back in the menus. Currently using March 12th CVS build.
As a side note, the new ccXStream 1.0.14 works great. Added '-march=pentium2 -O3 -pipe -fomit-frame-pointer' to the cflags....not sure if it speeds it up...but it should definitely be more optomized for my dual celeron box :-)