Lisa,
1) Download the latest UBBT 7.5.9 from the member area.
2) Rename your current smarty directory from "libs/smarty" to "libs/smarty757"
3) Extract ubbthreads-7-5-9/libs/smarty from the 7.5.9 archive and place it in to your install as "libs/smarty"
That should help get you up and running.
UBBT 7.5.7 - Smarty v2.6.19
UBBT 7.5.9 - Smarty v2.6.28
If you have any problems after that, just remove the new directory and rename "libs/smarty757" back to "libs/smarty"
HISTORY: When i upgraded from Smarty v2.6.19 to the latest Smarty v2.6.28 several years ago, my forums no longer crawled. So then I pushed for the current UBB.threads maintainer (SD, at the time) to upgrade the included smarty version within his next release from 2.6.19 to 2.6.28. That release was UBB.threads 7.5.8. Since I am now a maintainer of the current version of UBB.threads, since v7.5.9, I am also using this updated version of Smarty with each release. Going forward, I will be looking to keep Smarty up to date with the v3 series. But this will require a bit more work and also that the base install of PHP be version 5.2 or newer, for Smarty v3 to work.
