speedbar and gdba

[Hadron Quark]

I realise I'm probably missing something incredibly obvious here and
have googled away with no success:

if I debug in emacs using gdba (gdb), I can bring up speedbar view by
hiliting a variable and hitting C-c C-w for "watch".

But I'm damned if I can get the speedbar to expand and show the member
data!!!

Any hints & tips much appreciated.

I have tried hitting enter (prompts me for new value), clicking, double
clicking, right clicking  : nothing. There is a "+" there indicating it
can be expanded - but I get nothing.

Suggestions for tracking the problem down? Or is it glaringly obvious?