Hi there, got problems?
Well, when I bought my WS-EX it had this rather strange error that maked my WS to reboot when I changed to RAM #19. I was a little afraid to buy it, but someone told me that this was probably a software error. I was told that, "do a sysex dump with original sound, a sort of reset" and voilá it worked.
So my advice is, save your homemade sounds give the WS a shoot of sysex and I think the problem will disappear.
I can't garantuee, it but give it a try.