why i cant post on general servers?

[Arex]

i cant post a messagge on general servers,i get a strange error messagge...

[Belfedia]

It was a php error ?

If right i have the same error with some post...
Vbulletin forum software don't accept some type of character (latin)
It say, it don't found xxxx.php that annoying :(
I have made some thread about this forum problems but nobody
found a solution...

[Arex]

i already have found what is the problem, i cant use the letter "n" with the horizontal line on top, if i use it, i get this message:

Not Found

The requested URL /forums/newreply.php was not found on this server.