You use Itunes???

Hello,
Anybody ever had the problem of their itunes 7 no longer recognising their ipod???

This is a real headache...
My itunes "7" no longer recognises my ipod.
Two ipods frequently use the itunes; then one day when windows was starting i plugged my pod in. Opened up itunes only to see that it was calling my ipod my girlfriend's, and saying that the tracks on hers were actually mine....Disaster. Now, after a couple attempts of resetting and reloading, it doesn't recognise my pod at all in itunes, only as an external hard drive.
This means I can't add any music or even view the content when connected to my laptop, as itunes doesn;t recognise it at all.

Any ideas? Any help?
I sincerely hope you can help.
Cheers