iTunes suddenly won't recognize my iPhone


Feb 28, 2009
2 days ago, I upgraded my other music organiser, MediaMonkey - and iTunes suddenly stopped recognising my iPhone, won't sync and just gives the error message "iTunes cannot read the contents of the iPhone ... restore this phone to factory settings" bla bla bla
My phone is jailbroken and will take ages to get back to this stage
I also tried syncing on my other laptop, which doesn't have MM, but I get the same error message so it sounds like there's a problem file in the phone
I asked the MM forum and they say it's the first time they've heard of this happening
someone suggested deleting all my music on the phone- that didn't work
I've made sure MM isn't active when connecting iTunes but that doesn't help either

someone else suggested I download Total Commander, go to /iTunes_Control/iTunes/ and delete file iTunesCDB - is that a good idea?
can anyone think of why this is happening?
I'd really appreciate your help. It's been 2 days since I last synced and I've got withdrawal symptoms