I don't think it's a software issue. It's a strange problem, and chances are some physical componenets are going to have to be changed out, which will require servicing.
Contact Bamboo support to see if there's anything they can do (provide a reburnished swap, etc.).
Here's their web support page:
http://www.wacom.com/productsupport/
It might be better to consider buying a new unit if their replacement/repair price is too high.
Good luck, and hope this helps.