As far as I know, and I struggled myself with this problem once, the problem is that one of the hardware components you have in the puter is not understanding fully (bad written drivers, too old hardware ... ) the suspend mode. The only chance you have to get rid of the "locking" is to disable the suspend mode - directly in bios because one of the components does not support the S3 ACPI state (read here: _http://msdn.microsoft.com/library/default.asp?url=/library/en-us/kmarch/hh/kmarch/pwrmgmt_7e3r.asp)
PS looking at the configuration you wrote I suppose that the tnt is having problems, but it's just a guess ...
You also might try a bios update, maybe it works ...
good luck