arrow keys not working(some times) when I am using Firefox page up and page down also is not working(some times) Ubuntu 10.04 64 bit Firefox 3.6.8

[Tapas Mishra]

On my 64 bit Ubuntu 10.04
2.6.32-24-generic #41-Ubuntu SMP Thu Aug 19 01:38:40 UTC 2010 x86_64 GNU/Linux
I am facing two problems in using firefox

1) Arrow keys not working when I am using Firefox page up and page
down also is not working.
but this problem is not in Chrome version 7 on same system.

2) Some times when I type some thing in search box or some box using
Firefox for example when I was typing subject of this email
"arrow keys not working when I am using Firefox page up and page down
also is not working Ubuntu 10.04 64 bit Firefox 3.6.8"
after typing arr I kept typing rest of the subject line but nothing
came on the subject box
I had to finally open gedit and then type the subject to post.

What could be the problem.

The hardware is Dell Inspiron 1440.

-- 
Tapas
http://mightydreams.blogspot.com
http://wiki.xensource.com/xenwiki/Xen_on_4_app_servers