the problem you have- when you updated, one of the miles sound
file has NOT updated/updated properly (possibly because it was
still in use by windows).
there is only one solution that i can think of (and that dosen't
always work) - download the critical rebuild patch (its a big file,
sorry!). DO NOT install it (yet!). REBOOT/RESTART computer so that
no files from the game a still resident in memory/in use, then
INSTALL the patch. that should sort it out.
if it doesn't work(i did say it dosen't always work) then its the
old backup saves, haks, portraits, local vault, mods, etc..... then
uninstall. then delete the NWN directory (this gets rid of any
mismatched files that have not been uninstalled). and then
re-install. next reboot/restart computer (see above for reason).
then update game. bizarrely if you have a slow net connection (or
the update patch downloaded/saved (as a stand alone file) already)
this method is acually quicker/cleaner than the critical update
route.
does this help?