Network install broken ?

[Le grand pinguin]

Hello list,

i'm just tryingto install ubuntu using a network install.
Unfortunately the box freezes during the hardware detection
scan while scanning for disks - i've only attached one
20Gb harddisk that allready has partitions and filesystems.
Is there any way to keep the installer from scanning the 
disks? I'd rather be able to mount the partitions manually
(as i was with earlier Debians)? 

 TIA Ralf Mattes