FontForge keep SegFault while you select more than four points there and press some modifier like Shift or Control.
I found on FontForge's mail list patch for this, so I'm about put it there so you can put that into portage tree.
That patch solved this problem at mine side.
Steps to Reproduce:
1. Create new font
2. draw more that four points
3. select more that four
5. Press Shift
Link for Mail list thread
Created attachment 300183 [details, diff]
Patch for solve 5 points select and pressing Shift/Ctrl
Created attachment 300185 [details, diff]
Patch for ebuild fontforge-20110222-r1.ebuild
This was fixed upstream at some point.