most of the time your phone slows down because its full of shit, save stuff onto the memory cards and make sure you delete your cookies and cache if you use the web alot because it fills up you phone with shit and slows it down.
Dunno but I can't reply to your texts when it does it. Have you ever tried checking the message settings on your phone?
Check the stuff you got with your phone, or ring orange and they'll be able to tell you what the settings should be
i rang & them & they sent a text to me...cos i got that 1 they said there wasn't a problem even tho i had already told them it wasn't happening everytime
i can cos it only sometimes deosn't work....it could b that 3 people are trying to txt & 1 can't.... theres so many things that don't go quite right but only sometimes that it's hard to explain to the simpletons on the other end of the phone... it's like the mobile world of bt