Well, if there is only the manual option:
try:
/dev/sda1 swap 1GB(should be twice your memory size...but it doesn't really matter)
/dev/sda2 ext3 REST
that should do the trick...
I agree that you probably won't need the swap partition(it is probably more useful to keep your pendrive longer than to have a swap partition)
and I would create a dedicated boot partition just to keep things on the safe side...
/dev/sda1 fat32 100MB <- boot
/dev/sda2 ext3 REST <- BT4



then go with the automatic partition editing instead.
