this sounds similar to my case.
i'm trying to delete a thread of about 1600 messages and it refuses to delete them. the stock messages application will give me the option to "force close or wait". if I keep pressing "wait", the application will suddenly crash after awhile leaving all the messages intact. if I choose force close, all the messages will be gone but i can't send messages; so, i'll restart the phone and all the messages will return.
i've experimented with clearing user data and cache out of various programs related the sms but had no luck. there might still be a solution to quickly clearing the sqlite table.
i also tried using the app "sms quick delete" to delete the entire thread but it gets stuck at 0% on the progress bar, then it will display just a rotating circle after awhile.
Here's the solution to deleting large threads...while using the "sms quick delete" app, enter the thread so you're looking at each individual message, then press "select all" and Delete. This will begin to SLOWLY delete each message but should speed up after an adaquate number of messages have been cleared.
