Installing fedora 3 on USB2 hard Disk;

[Mirco Scaramucci]

I have been trying to install fedora on an external USB2 hard disk but 
it seems as if Fedora doesn't even see this  hard disk at all.
Booting from USB devices is definately enabled in BIOS settings, in fact 
if I try and install a version of Windows XP, it does recognize it and 
offers to install on such hard disk.
In fedora, when getting to the stage where I have to choose hard disk to 
install on,  I only get the internal hard disk option.
Is there any work around way of doing this?
I have a Dell Optliplex GX270, Pentium 4 2.25Ghz, 760mb ram, Integrated 
graphics, C-Media Sound card.

Thanks

Mirco