HTC Mogul / XV6800 / PPC6800 / P4000

I have had this phone over a month now and enjoy it. However there are a couple of things I need help with. First, if someone sends me a 2 page txt msg it does not come thru..I get a second msg saying the previous msg had to be modified. Any suggestions? Second, I have looked in notifications and every where else....how do I turn off the notification when I send a txt (vibration or chime). Thanks in advance!