thunderbird and seamonkey inaccessible on 64-bit karmic

[Aaruni]

-- 
aruni
http://aruni100.googlepages.com

ph: 0522 4042921, mobile: 09335844700
c-103, sec H, Aliganj, Lucknow--24
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Hello, I am using 64-bit and have had a good experience so far.
However, If I try to use thunderbird or seamonkey orca would simply
announce inaccessible when switching back to the application window as
it doesn't talk in the first place. How can I fix this?
Thanks,
Aruni.