Vanishing hard drive post W7 install

Hi all,
I'm just finishing a nearly fault free clean install of W7.

However, I've one major problem.

I've got three hard drives inside my desktop. One which I've installed w7 on, a second used to store pics and documents and a third for music.

Unfortunately, the third, which is full of music, is not being recognised.
It shows up in device manager and showed up in the initial instillation when choosing where to install W7. (it was working fine under vista)

It is the only one of the three which is still using an ATA connection, the other two use SATA. Below are my three hard drives, the WDC is the one which has vanished.

Maxtor STM3250310A ATA Device
Maxtor STM3250310A ATA Device
WDC WD2500JP-22REA0 ATA Device

I fear that it's gonna take a format of the drive to 'regognise' it properly within My Computer. I've got 98ish per cent of all the music backed up but I don't relish spending an afternoon copying it back across from DVDs.

Has anyone got any advice on anything I can do to make it appear properly.

cheers,
Dave