abbrevs are not expanded with <SPC> in debugger(gud) mode

[Pawel]

Hallo group members.
I added the following abbrev to debugger (gud) mode.

(define-abbrev gud-mode-abbrev-table "ir" "info reg ")

It is expanded using C-x a e, so it got "installed" properly.

Unfortunatelly <SPC> does not expand it.

Just to compare, I added the same abbrev to c-mode and expansion with <SPC> 
works fine there.

In both the modes, <SPC> key is handled by:
self-insert-command

In both the modes, <SPC> belongs to " " class ( Command:(string (char-syntax ?\ 
)), returns " " for both the modes).

Have You got idea what is the reason?

Regards,
Pawel.