I have an unlocked/jailbroken 2g

Question

I have an unlocked/jailbroken 2g iphone with 2.0 version. All aspects of iphone work except music module. Itunes on my PC will not access iphone - wants to restore which would cause data loss and brick. I can download music directly from the iphone but I cant exchange with PC. Other programs show music on phone that I also cant access. I can only see music that I have downloaded directly to the iphone. I have itunes 8.0 - tried to go to earlier version but when I did itunes said it could not read the files because they were created with a newer version. Can u help? Is there any way to at least backup the data?