Hey Im not sure which mod is lacking the missing file (maybe better sounds?) but when I enter Desele's House of Earthly Delights in Suran it pops up with a missing sound file error.

look for last lines of Morrowind\Warnings.txt, there may be the pertinent exact error message which you can post
exact error message = more chance someone can find the problem

Solution here:

http://morrowindoverhaul.net/forum/index.php/topic,1561.0.html
Next version of MGSO will correct it.

^ok just figured out you need to register to see attached files...Thanks alot!