[ubuntu-in] Missing Thunderbird

[Ramnarayan.K]

Hi

A friend (whose malfunctioning grub problem i mailed earlier, is
unable to install Mozilla - thunderbird because it does not appear in
Synaptic, it shows up in Ubuntu Software Centre but is greyed out, not
allowing him to install.

he has checked all the default repos but still Thunderbird does not appear.

Any idea which repos (or ppa) he needs to add so that he can get Thunderbird.

He is currently running Ultimate 2.4 (based on Ubuntu 9.10)

thanks
ram