Math Forum http://mathforum.org/kb List of forum topics en cell merge bug not only when merging cells http://mathforum.org/kb/thread.jspa?messageID=7934022&tstart=0#7934022
Enter the following three lines in an input cell:

a=1;
(* comment]]> Dec 8, 2012 1:28:47 AM Dec 8, 2012 1:28:47 AM F.H.Simons@tue.nl 0