Blackberry browser 400 error - socketexception Connection reset
 

I'm managing a Blackberry Enterprise Server with Exchange connector that I'm learning about. Several phones have problems accessing websites (8330 Curve for one) when using the Blackberry browser ... they receive a 400 error: socketexception: connection reset error. When you use the internet browser, there's no issue. The websites happen to be located within our network that are having the problem. I just upgraded from 4.1.3 to 4.1.7 to see if it would address the problem, but it's still happening.
Thanks for any help.