CASE*Designer for DEC's on Xterms...problems

G'day,
We are running CASE*Designer V1.1 on DEC 5000 workstations (running Ultrix 4.3) at this Uni, and I'm trying to get CASE*DES to run on some PC's set up with Linux and Xterm's. I can get the case front screen (the "flying grid") to come up with no problems, but when I try to use one of the tools (e.g. the data flow diagrammer), the selected tool box appears for < 0.5 seconds, then disppears, leaving me back with the case front screen. Any ideas as to why this is happening ? The case tools are running on our file-server, and the client machines xhost to the server, telnet to the server and then setenv DISPLAY client:0, where client is the name of the client machine. Cheers,

--
  ,-_|\   *********** Rocqueforte Daemaen Alexander O'Leary *********** 
 /     \  B.App.Sci.(Comp),BPFH,Uni. Of Western Sydney,Nepean,Australia
 \_.--_/  E-Mail: roleary_at_st.nepean.uws.edu.au  Work Phone: 047 360 773 
      o     "Life^H^H^H^HHonours is a lemon and I want my money back!"