@tranzz: Not very helpful. Since it could be an application causing his problem, there is no reason he shouldn't post in the Applications forum.
@jacque: I don't think I can help you directly with this problem, hopefully someone else here can. If not, you can try asking here: chompSMS
These appear to be the official ChompSMS forums.
As a worst case scenario, you can try backing up all your data and programs (There are backup apps in the MarketPlace, I don't have access to paid ones, so I'm not sure which is the best. Astro File Manager will back up apps, and it's free) and then reset your phone back to a factory reset. I don't know how this is done on the Hero, but at least you would be starting from a "new" phone.
First try contacting ChompSMS directly to see if they have seen this before. let us know if you find a solutions, as others may find it useful.