It seems to me you're going about this the wrong way. Surely it would be better to ensure there is always a space (if appropriate) before and/or after whatever the problem content is at the time of insertion, rather than trying to clean it up afterwards.

Regarding punctuation issues (which are broader than just 'the beginning of a sentence following a blank row'), those can be handled by the use of an appropriate wildcard expression that tests what the preceding character is.

As for case sensitivity, 'MatchCase' doesn't work with wildcards - wildcard expressions are always case-sensitive.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]