[Bradford] Dead icons in Lyx toolbar

[Devo Too]

Hi Folks,

After a fascinating introduction to Lyx/Latex/Tex by John at Tuesday's 
BradLUG, I installed Lyx on the PC and, having finally got the laptop 
into a functioning state at the same meeting thanks to David, Lyx on the 
laptop too.

Initial results using the PC were terrific and easy to achieve. But 
copying the draft report to the laptop, the first four toolbar icons* 
are dead.

Tried going into the dropdown menus to get a view of the PDF outputs, 
which didn't work either.

*The icons are "View" (pdf output - image of two eyeballs), "Update" 
(image of two arrows forming a circle, like an old fashioned browser 
"refresh" button), "View master document" (two eyeballs on a file cover) 
and "Update master document" (old refresh arrows on a file cover). The 
third and fourth are also inactive on the PC, not used anyway so not so 
bothered.

The first one, though, is used constantly.

I've searched on various terms to find answers, checked permissions, 
double checked to ensure I installed at least the same programmes onto 
the laptop as on the PC (although Latex was already installed when I 
started putting Lyx on the PC), dug around in a few file systems hinted 
at here and there as I've been reading. These were mainly Xorg and 
Nvidia, one of which I still suspect may hold the solution.

Is this a hint? Sometimes when closing Xfce the ystem comes up with a 
line containing "Waiting for X server to shut down: fatal 10 error (or 
error10?): resource temporarily unavailable - which goes on but runs off 
the screen so I can't see the last part.

Both boxes have Arch installed. The PC has Gnome and the laptop has Xfce 
as its GUI.

So can anybody please point me in a direction which may prove fruitful 
in solving this problem?

TIA,

Mike