[acontrasto]

I was having the same problem. Yesterday I installed microsoft's MyPhone and all of the text messages were synchronized, then I archived them. The next time my phone synced up with MyPhone the text messages were wiped from my phone and now I no longer have a lag issue. I was just going to delete them all anyway, because I had a feeling it was due to the massive amounts of text messages that was causing the lagging. I had over 3000 saved. They were all in the conversation format, so I'm assuming it takes a good deal of memory to remember the structure and organization of that many text messages every time the Messaging center is opened.

If you don't mind losing your text messages, try deleting them all. If you want to save them, back them up with either myphone or something else and then delete them. I think you'll be surprised at the difference.

Also try removing some of the old email.