internal errors in inkscape

[seasame]

i am using macbook pro with updated OS

i have been able to take pdf, to inkscape to SCAL with success.

I am now attempting to be a little more creative in inkscape - but when i click on tools (circle) and then stroke/fill i get:
internal error

Inkscape encountered an internal error and will close now.
Automatic backups of unsaved documents were done to the following locations:
New document 1.2009_07_18_12_50_57.0

also when inkscape is running the print is jumbled till the cursor is over it

thinking about deleting inkscaped and reinstalling

any other suggestions?