After perusing the web for possible solutions to this problem i discovered that the drive was set to CSEL and the reason why the toshiba wasn't detecting the drive was because it needs a specific master/slave setting.
So, the solution was to 'force' the drive to become a 'master' by earthing pin 47 on the IDE interface. This can easily be achieved by opening up the drive and (i'm not kidding here!...) stuffing a bit of tinfoil in between pins 47 and 45 (which is earthed) and covering the foil with a bit of blu tak to keep it in place.
Put the drive back in and 'hey presto' drive is now recognised! :bigsmile:
Once i get hold my soldering iron, i'll create a more permenant solution.
Hope this helps anyone.