[orca-list] thunderbird search combo box partially inaccessible in version 3.1.7

[hackingKK <hackingkk gmail com>]

Hello all.
Firstly I would like to ask on the outset if Thunderbird 3.1.7 is the 
correct version in terms of accessibility?
I have it With Vinux 3.1 based on Ubuntu 10.10.
If yes then could some one help me understand how to use the search option?
There is this search all messages combo box which I can properly locate 
for sure.
With Thunderbird 3.0, I could just press alt + down arrow to get the 
list of search by choices.
I would get subject, message body etc as choices.
So suppose I am searching for a word in the subject itself I could 
choose the option from the dropdown and hit enter.
But now I don't get those options.
Has any thing really changed or is the feature broken in terms of Orca 
and accessibility?
I have herd people using TB 3.1.8 which I presume has the bug fixed.
But I did not find a way to install it on the machine.
Happy hacking.
Krishnakant.