> Maybe you turned on scanner's advance option 'decompress chd and check sha1/md5'
> which does the same as chdman -verify. And that check takes some time...but
> still it's fast..nothing 'hour-like'.

There is an option for "Additionaly test SHA/MD5 for matches" but nothing specific to CHD decompressing. I disabled it anyway, same deal. I have however marked the option "Allow DiskImages in ROMPath root".

Edit: I found the option you mentioned under Checksums... and it wasn't marked.

> If that deep-check option is turned off and it takes remarkable long on your
> system, something other may interfear (maybe a virusscanner trying to analyze a
> chd). Turn other applications off.

Turned off AVG 7.5 which never game me a problem before, didn't help either.