i had the same problem while trying to open up text messages. i get a lot of text messages, so i tried deleting most of the older ones, and that solved the problem. now my texts open very quickly again. so try this from the text menu: under options>general options set "keep messages" to 15 days. this is the lowest setting. if this is still not deleting enough for you, you will just have to manually delete extra texts to speed up your performance...
I had this problem a lot on my Pearl Flip, I think it has more to do with how many other texts are from the same person. If it has a lot to go through it can slow up. I figured it out when it would always freeze up when I got another text from my gf or something but if it was a brand new text with no other history then it would be fine. You can either just manually go through and delete old texts, if it gets to that point on the Tour which is a lot less than when it did it on the 8230 I just go to the previous day and delete all prior. You can also go into the sms text settings under the setup part of the phone and you can disable previous texts or choose how many it displays and that might help it .
