hi Tom, there is only a couple of things that can cause "choppy" sound,
bad driver, low memory,bad recording,low bandwith
driver = yus worked before, any new install since??
memory = make sure ivm runs in high or more process level, default is normal.
sound = listen to your sound file with wmedia or something other than ivm, ck 4 quality
i dont produce wav files with ivm, it can but its not designed to do so, try this "textaloud",
stay with wav if you have plenty of space and not up/down loading files. "min compression"
disable ivm service, run fore ground only. several reasons here among is license ckeck.
ivm moved system file location from what they state in help files, before u reinstall, make sure yu have good backup.
i don't think i saw good uninstaller "how-to" in here, that included licenses key and register info settings removal.
try this for starters
ps is yur pc dedicated