[CentOS] Thunderbird Upgraded from 1.0.8 to 1.5.0.4 and MOZ_NO_REMOTE dead

Since Centos 4.3 comes with Thunderbird 1.0.8,  I downloaded the tar of
1.5.0.4 fro mozilla and tried to figure out what to do with it.

per http://www.mozilla.com/thunderbird/releases/1.5.0.4.html#install

I was just suppose to copy the files....

In the end I put it in /usr/lib/thunderbird

I am NOT a Linux guy so could not figure out how to properly replace
/usr/lib/thunderbird-1.0.8 and /usr/bin/thunderbird...

So I setup the following script, acct1mail:

set MOZ_NO_REMOTE=1
/usr/lib/thunderbird/thunderbird -profile ~/data/acct1/Mail &
set MOZ_NO_REMOTE=0

and acct2mail

set MOZ_NO_REMOTE=1
/usr/lib/thunderbird/thunderbird -profile ~/data/acct2/Mail &
set MOZ_NO_REMOTE=0

In 1.0.8, running these two scripts (mozilla-thunderbird -profile
...)and have two copies of Thunderbird running.

with 1.5.4 the second script gets:

Warning: unrecognized command line flag -profile

And focus returns to the running copy for acct1.

Advice?