Log IN Time Outs

Can something please be done about being logged out of the system after a relatively short period on apparent inactivity. I have just been composing a long reply to a thread and when I posted it I have lost all the content on my post which is very frustrating. I don't feel I should have to compose replies in Word and then cut and paste. Most forums allow an always connected log in, can we not have the same thing? Or at the very least have a 3 hour window without the need to log back in.

David