Problem with hard drive and dvd drive

I have Three drives on my computer (All IDE) a DVD Drive (Master Secondary) a CDRW Drive (Slave Secondary) and a new 80GB Western Digital Hard Drive (Master Primary) Now here's the problem. Now after putting the new hard drive in, Whenever I pop a CD into the DVD Drive, nothing happens. The DVD Drive is detected by Windows and the drive is in My Computer, but nothing happens. The same thing happens if I switch the CDRW to the Master and then the CDRW Drive doesnt work properly. Now the way to get a round this I've found is to make sure that there is a CD in the DVD Drive when my computer starts up. Why is that? and is there anything I can do to fix the problem?
It might be that your BIOS is detecting the DVD drive as if it were a hard drive, thus when there is no CD in the drive at start up, it thinks there is no "hard disk".

Go into BIOS and turn off Auto detect for the secondary IDE channels and force it to detect it as a CD Rom drive.
Maybe you've got your master drive/slave drive jumpers mixed up ???

Make sure the slave drive is set to "slave", or try using a different IDE cable. If you're feeling brave, you could try re-flashing the BIOS with the most up-to-date version (NOT for the faint-hearted

Of course, there is everyones favourite fix-everything solution - reformat