is it just posting on forums that has problems, or is it safari generally?
i only ask as i have two ipads and an iphone here all working fine on safari and iOS5, but i use tapatalk for ukgser. maybe i'll have a bash on safari later.
Edit: Had a quick look round, and most likely looking cause I could see was to do with ICloud bookmark sync. Some people have turned this off on iPad and desktops, and the crashing has gone away.
I might further suggest checking that any icloud accounts are set up identically. From recent personal experience, I know it is very easy to create accounts on different machines with different logins, as apple autofills with the wrong info. It can cause all kinds of strang behaviour if that is the case.
Now posting from safari/iPad.