I have seen this bug reported a couple of times, but closed with the reply that fdisk is available from expert mode. However, expert mode requires a driver disk, which I don't have. So, I had to CTRL-ALT-F1, mknod hdc, and fdisk hdc to get it running. I would find it a lot nicer if you could put an fdisk option somewhere around the partitioning part and label it "fdisk: experts only" or something similar. Otherwise, the new GUI installer is awesome!
Are you sure that expert mode needs a driver disk? I just select the "Cancel" button and step straight through that without one...
Err... no, I'm not sure... It sounds so obvious when you point it out, but I never thought of just hitting cancel. But if hitting cancel is enough to get past that screen, and the rest of the install proceeds just as it does in non-expert mode (I have no idea whether it does), maybe the text on the "cancel" button should read "Continue without driver disk" or something similar. "Cancel" tells me that I can either insert the disk and proceed, or cancel the install if I don't have a driver disk.
This issue has been put on a list for future features.
fdisk is available as an option in 6.2.
The problem here is that it should be more obvious how to get out of the Driver Disk screen if the user does not have a driver disk.
*** This bug has been marked as a duplicate of 6476 ***