Hey
Just something I noticed, but both my wifes and my cell phones were losing a few texts after porting our numbers to 2 degrees, which seems to be a reasonably common problem.
The problem seems to have become better after associating our numbers to the sim card and enabling text on roaming through the messaging app.
I had to download an app on android which fixes the phone number on the sim card but I think Nokias and iPhones have this build in. Worked on a u8150. It also allowed me to have my picture on the message app, which is fun.
App.
There may be another, 2 degrees back end type, reason why things are now working better and I'm sure everything is more complicated than this, but it cant hurt to try and see if it helps.