Fix memory management bug when getting widget context.
Fix memory management bug when getting widget context.

darcs-hash:20061017203806-91c87-2abd3c26f2f55d5913cecf9bfcde5e418c7b7e12.gz

thiagoarrais/gtk2hs,thiagoarrais/gtk2hs,thiagoarrais/gtk2hs