Problem receiving text messages on IPhone 2G

Had purchased an IPhone 2G about a month ago or so. At the time I had an account with Verizon.
I jailbroke the IPhone that way I could get T-Mobile service. I had the number ported over to the T-Mobile service. It took 24 hours or so in order for me to start receiving text messages from Verizon customers. It has worked perfect since then, but just the other day I started getting some messages and not others. I know its not the service, tried turning the phone off, made sure my friends were receiving the messages that I had been sending out.

I called T-mobile about the issue, they said there is no problem with the service. I have no idea what to do, should I try to restore and then reinstall the software? If so how exactly do I do that? Any help would/suggestions would be very helpful. Like I said it just started doing this a few days ago. The weird part is that I get some throughout the day, and have asked friends if they have sent messages to me during the day in which they have. Thanks

-Tyler