Thats actully (If I understand what I did correctly) only a limitation of the 3.1 ROM. Which can be bypassed with about (if you have done it before) 10 minutes worth of work.
Basically you setup the first part of the drive by only using 4 or less gigs. preferably with a setup like this...
first partiotion DH0: 500MB or less
Second Partition DH1: 3.5G or less
third partition DH2: rest of the drive.
And then you can load a module that overlays on the Roms limitation in the first partition and also update a file system in the RDB I think it was called. Theirs a Post from Thomas on here that has the complete instructions.
Click here for instructions.Wish the mods would have sticky-ed that its a great information page by Thomas and I even through in 1 useful thing myself. Not terribly usefully unless you have Vista but still there to help.