on the new 2.5 update SMS works fine, with and without the JD Arcsoft (About to test MMS) but SMS does NOT work in the threaded 2.5 sense's UI (Though it looks 29382983 times better than how it was before, and its much faster
) But if you click compose message and write an SMS it will send, haven't tried in classic winmo texting yet
So basically, if you click on their name and the threaded UI pops up, your text will save itself in the outbox and screw up your conversation with that person and just leave a phone number, but if you go to traditional and not conversation mode in Sense's texting, its fine. Or if you send your SMS through the "Compose Message" on the conversation tab its fine. Hope this helps
EDIT: Tested MMS and it works fine also