No. You can’t restore FreePBX 2.8.1.4 onto a FreePBX 2.9 system.
You need to install FreePBX 2.8, then upgrade to 2.8.1.4, then restore. After that use the Version Upgrade module to upgrade to 2.9
ok on a test system I was able to restore our backup to a 2.8.1.4 system.
then from there upgrade to 2.9.
Our production system seems to be somewhere in between 2.8 and 2.9 . sympotoms of that are in apache2 error logs like:
[Sun Sep 18 10:14:12 2011] [error] [client 173.48.186.201] PHP Notice: Undefined variable: fromstatsmonth in /replica/var/www/admin/cdr/call-log.php on line 370, referer: http://phonesys:1780/admin/reports.php