HOWTO debug key events?

Hi! I would like to investigate the cause why XEmacs 21.5 (beta6) "bok choi" [Lucid] (i386-unknown-freebsd4.6, Mule) of Tue May 14 2002 on viteno.dyns.net in TTY mode RET sometimes isn't interpreted correctly. Eg, % xemacs -vanilla -nw M-x report-xema TAB RET and nothing happens. If I press any other key, the action is performed and I'm prompted for the report's subject. Where would be a good place to hook into the system? BTW, the key sequence of the above operation is ESC x r e p o r t - x e m a TAB LFD Thanks, norbert.