I'm having the same issue with my Alltel 8130, can't send or receive attachments via text, only email. And even then...99% of the attached I receive via e-mail don't even work, as if they're not there or something.
I called Alltel numerous times and keep getting told "RIM said they're almost done with the software update, should be another month"...and it's been 6months since my first call-in.
I called RIM the other day and they said "It's Alltel holding the update back, call them".
It's amazing how much they're willing to help us Blackberry owners out.