"Not enough space" on partitioning? I have a 320GB harddrive with 95GB free.  I boot to a 10.5 disk, open disk utility, and add a 40GB partition.  Halfway through the progress bar, though, it tells me that there's not enough space.  I'm not sure what it means- I'm just splitting my free space off to another partition- it shouldn't need any extra space.

Any ideas as to how I can partition my drive?

Clarification: this is my laptop's internal drive- the one I boot from.  I can't boot normally and partition with /Applications/Utilities/Disk Utility.app.
Ok, solution found on an old superuser question, posting here for posterity.

I just needed to defrag the thing

I got Coriolis iDefrag.  I ran that on the compact setting (required restarting into it's own special mode, but no disk burning was needed).  A few hours later I tried to resize the partition and it worked fine.