improve return-node CSE, don't CSE 'Store's necesarily as it can lead to space leaks.
improve return-node CSE, don't CSE 'Store's necesarily as it can lead to space leaks.

darcs-hash:20070605224326-1a7c6-9bb8d97f397084ecc38111deae4b7d5653975a58

jimcrayne/jhc,jimcrayne/jhc,jimcrayne/jhc,jimcrayne/jhc