It sounds to me like something's fouled up.
Do you have another lens you can mount and see if the problem follows your lens or stays with the body? Or if not is there a shop or a friend nearby with a lens you can use to troubleshoot?
Short of that it seems like you need to get it looked at. If you're in the US i've sent my Hasselblad gear to David Odess, he does a great job with repairs and CLAs.
http://www.david-odess.com/
No affiliation - just a satisfied customer over the last 10 years or so.