Help Vibrant mms with Bell Mobility

I have had my Vibrant Galaxy S for a couple of months with Bell Mobility.
I have noticed that I am not able to receive picture messages from any of my friends (on different networks) although I can receive them from my dad who has the same phone and is also on Bell.

This is quite frustrating and I would like to know if it is Bell, or there is a setting on my phone that isn't turned on.

Thanks so much!
I am in the same boat. Except across the country I can't recieve the pictures but I can send them. Though I have not tried recieving from anyone on bell myself.