strange problem with proxy settings in IE


Bring mich zum Licht!
I am using a Proxy to connect to the Internet.
Everything is working fine.
but as soon as I write some IP adresses in the field to specify addresses where the proxy should not be used, IE quits when I try to get on a site as soon as I type in the address and hit return. It does not matter if the site is listed for proxy use or not.

Taht is really strange...