update for linux x86-64

Hi,

a few days ago my Thunderbird 3.0.1 on linux x86-64 (Fedora 12) notified
me about updates for my add-ons. The update to enigmail 1.0.1 (from
1.0.0) failed, though. I was told that the new extension is incompatible
because of the architecture. Obviously, it tried to install the 32-bit
version. I downloaded the x86-64 version from
http://enigmail.mozdev.org/download/index.php and installed it manually,
which went flawless.
Is this some wrong setting in my setup or is an automatic update for
x86-64 currently not possible?

Regards,
Jakob