I have a 32gb iPhone 4 running iOS 4.0, recently jailbroken. I initially had the missing FaceTime and mms but installed the fix from cydia. Today I synced my phone and I keep getting the "SMS mailbox full" prompt asking me to delete messages. I went on and deleted atleast 1000 messages but I still get the error. A respring, reset, and a power cycle don't seem to fix the problem. I'm able to send messages and people receive them, but I can't receive any responses. I have sent nowhere near 75000 messages either. Is there anything I can do to fix this issue? Thank you!