"X11 connection uses different authentication protocol"

I am trying to run a remote application over ssh tunneling.
Everything works except for ONE application. I can execute xterms,
xclock but when I try to execute "xelga" a mentor graphics application
I get an error:

"X11 connection uses different authentication protocol"

debug3: fd 8 is O_NONBLOCK
debug1: channel 1: new [x11]
debug1: confirm x11
debug2: X11 connection uses different authentication protocol.
X11 connection rejected because of wrong authentication.
debug2: X11 rejected 1 i0/o0
debug2: channel 1: read failed
debug2: channel 1: close_read
debug2: channel 1: input open -> drain
debug2: channel 1: ibuf empty


All other mentor graphics applications work. Anyone with any insight
have any ideas? Has anyone ever seen this error specific to
specialized applications? or any applications in general?

.