I'm getting no text messages .....

[sdruid]

I'm getting no text messages, and when I do get any - they are several hours overdue or late, or from the previous day for that matter.
I was on the phone with Verizon and they had me do an over the air programming which fixed the problem only briefly....a few minutes later the problem returned....no more text messages....
I think the rep said something about the radio....could this be my problem ?
How do I tell which version of the radio I have and how do I upgrade ?

Thanks...