RDS Slow internet connection from Session Host server

Hi

We have a implemented a suite of HP thin clients running from a single session host server,  we use RemoteApp to give students a basic computing experience.  All works well except that we get slow internet on these thin clients. Internet in the school is generally fast. 

I then tested by logging into the session host box and tried browsing the web and again pages comes up very slowly.     We connect to the internet via a smoothwall proxy server.

If anyone can through any light on where I should be looking would be most grateful.

Thanks in advance

kevin

Kevin Sait