When running vnc or nxclient on my new (uptodate as of July 2010) Centos 5.5 install on my laptop (Asus G2K), all of my control characters are received on the server as the equivalent plain character. If I bring up a command-line window (bash) in the VNC or NX client display, and I type, say, ctrl-b it is received as just 'b' by the server-side command-line window.
I am using Centos 5 on both client and server, with dual-head display running Xinerama (on both actually).
If I ssh in to the other machine not using VNC or NX, everything is fine. VNC viewer/server work fine on all my other installs of Centos 5 as it has for years. It also works fine if I run VNC viewer from Windows from this or another laptop from the same location. Switching to NX client and server did not solve the problem, which suggests that it is something happening in the linux part of the configuration.
It seems there should be a simple answer, but I have hunted around in the config files and I can't find a likely place to tweak.