Windows 7 64-bit Support

Does the X1 6.6 client support Windows 7 64-bit?
I recently upgraded my XP machine to Windows 7 64-bit and moved my X1 v6.1 (build 3575). It installed okay but seems to be unreliable. It rebuilds the indices often, seems to be behind mail, etc.
If I buy a new version 6.6 will it fix these issues?
Many thanks, Peter
I recently upgraded my XP machine to Windows 7 64-bit and moved my X1 v6.1 (build 3575). It installed okay but seems to be unreliable. It rebuilds the indices often, seems to be behind mail, etc.
If I buy a new version 6.6 will it fix these issues?
Many thanks, Peter