Woohoo - fixed - apparently, this has something to do with the changed camera position adopted by GW - see this thread for the fix that I stumbled onto over in the mods forum:
http://www.subsim.com/phpBB/viewtopic.php?t=50341
I D/L'ed and tried the JSGME version of the mod/fix that jcwolf came up with as noted in that thread, and just ran a brief test in my Type IXB - no see-through watch crewmen anymore
Thanks jcwolf - that as driving me crazy.