Well MySQL 5 is faster than 4 (Rick or Gizmo may be able to shed light on the MySQL version as it may be too low for UBBT 7.2.2)
Also you did not list the actual version of PHP but many sites claim that 5.x is much faster than 4.x
SD seems to know a bit about MySQL/PHP so he might be able to help.
There is also the Dev site, but most of those guys also frequent this site as well.
I would love to help, but I'm not qualified to make such tweaks, just know enough to be dangerous
