Hmmm... if Handscent and the stock Message app don't do it, then I wonder if it's a setting thing...
I just a clean install of GoSMS Pro on my other phone (also a Rezound on stock ICS) and tried several messages, and I am not seeing this behavior... perhaps something is off in the settings of Go SMS? The only I see that makes me think is in Settings-Advanced-Application Settings and Message Grouping, it is enabled by default in mine. Otherwise, try a Clear Data on the Go SMS Pro app maybe?