Can't enter values in Tool Options boxes or Command Line

[RayArdia]

Have suddenly lost the ability to enter values in the Tools Options boxes, and can't enter anytjing in Command Line.
Using Ubuntu 9.04 and Qcad Professional.

[RayArdia]

Further to my last post:-
Have tried reverting to default settings - no change.
Re-installed QCAD 2.2 no change.
Tried using different drawings, starting a new drawing, but am still unable to enter ANY values (eg distance in Tools Options menu for a Parallel line) nor instructions etc in the Command Line.
Can anyone offer any suggestions please as I'm really not able to use QCAD without being able to input values etc.
Ray

[RayArdia]

In addition I downloaded the demo and community versions of QCAD to see if the same problem occurs - it does.
BTW, although the documentation seems to suggest that QCAD installs itself in /opt, my three versions reside in my home directory:-
ray@ray-laptop:~$ ls
Block door lh 620.dxf Outgoings 2008.ods
ChangeLog out.pnm
Desktop Photos
Digibox resetting.odt Pictures
Documents qcad-2.0.5.0-1-community.src
Door 720.dxf qcad-2.2.2.0-1-demo.linux.x86
dvd_udf.c qcad-2.2.2.0-1-prof.linux.x86
dvd_udf.h qcad-2.2.2.0-1-prof.linux.x86.tar.gz
examples.desktop README
First Floor Copy 2.dxf regionset.c
First Floor.dxf Second Floor.dxf
Geneology Symtronics Wind-up page 2.pnm
googleearth Templates
google-earth Videos
House Ground Floor.dxf Whole House 2.dxf
Income 2008.ods Whole House.dxf
Makefile William Coomer Census 1891.pdf
Music
ray@ray-laptop:~$
Should I attempt to place them in /opt, or doesn't it matter?