davidofkent said:
Many thanks for this. I followed your instructions. While TC still refused to unmount without forcing, a day later it suddenly began to do this withot any trouble - hence I thought the solution had been found. Very pleased!
However, to my amazement, and disappointment, the same problem has now started again (just to be sure I have checked the 'Allow Indexing Service' and it is still unclicked).
If anyone can help, I would be very grateful.
Thanks
Had the same problem for a long-time now. Didn't find any clues searching on the internet. Recently, I disabled the AV other background programs and went through the "services" list disabling possible problem services one by one testing each trying to dismount. Surprisingly on the list I found "Defragmentation-Service" - "Ashampoo Defrag Service - powered by mst software". Disabled this and TrueCrypt Dismounted without any problems. Thing is I didn't even Install any defrag software! This was installed as part of Ashampoo Uninstaller. So in your case, it could also be a bad software like this causing the problem.
hope this helps