iPhone 3GS won't update after jailbreak and restore

Hi guys, I have an iPhone 3GS and after updating to iOS5, performed a tethered jailbreak. I got bored of this after a while so attempted a restore to iOS 4.3.5. There was an issue with the restore, and now the last back-up I can find was from exactly 1 minute after the restore completed. I then tried to update my iPhone to iOS 5.0.1, so I could then use my iCloud backup, but when I try and update iTunes comes up with an "error -5000" code, which I can't find on the apple site or anywhere else. I just want to update to iOS 5 and get back my apps, contacts, photos and texts if possible. Can anyone help?

Thanks for reading,

Charley

I didn't think of that one, I'll give it a go with the other household laptop.