SBlueman - I believe the issue is related to non vB 3.8 installs, although some vB 3.7 installs have said the vBAdvanced install is working, perhaps between one of the 3.7 versions code changed between vB shifting save_settings(). This is a default vB function so isn't really an issue with vB Optimise, all I can say is try upgrade your vB to the latest vB 3.7 install
maidos - Your forum is executing a lot of queries, the two that this mod reduces will barely impact your forum because it is nearly executing 60 altogether. You really need to drop mods on your forum that are adding so many queries.