Clipboard is bent

[cr <cr@orcon.net.nz>]

(Next instalment in the fixing-my-desktop saga)
Not sure if I should be asking on this list or a Gnome list, 
but can anyone tell me where to start investigating my clipboard?
(I'm running Woody, and Gnome 1.4.)

My clipboard works for some apps but not others.   To take 6 apps at
random - Opera's address (URL) bar, Konqueror's address (URL) bar, 
Kmail's message editor, Kwrite, gnotepad+ and gedit   -
Copy - Paste works (or not) as follows:

Opera -> all others - works
Kmail -> Konq and Kwrite works, others not
Konq -> Kmail and Kwrite works, others not
Kwrite -> Konq and Kmail works, others not
gedit -> all except Opera, works
gnotepad+ -> all except Opera, works

To put it another way, the KDE apps will read anything; Gnome apps 
will read each other and Opera; Opera will export to anyone but won't read 
a thing.   Please nobody tell me that KDE don't talk to Opera, because they 
were all happily doing so under Red Hat 7.2.

cr

(That is, 'cr' as in Chris Rodliffe, not C-R as in Challenge-Response, which 
is nothing to do with me   ;)