I also have this problem on Windows 7, 64bit with both the Bitcoin-Qt and Armory-clients installed not on default locations.
Else it works, but this constant rescanning upon each start make it practically useless for me for "fast" transactions.
For offline wallets it's ok to wait for me.

It would be great if this can be fixed, maybe by checkpointing and a Merkle tree hash upon all successfully validated transactions.