Here's one that probably will only affect the more advanced FREDders amongst you. The big problem with the way the argument SEXPs work for many FREDders is that the inner and outer loops are the wrong way round. The game will execute each action SEXP for all the valid arguments first and then move on to the next one. Most users are expecting the exact opposite, All of the action SEXPs for each argument and then move on to the next argument.
This build uses a argument in the newly added mod.tbl to switch the loops around. Since this problem only affects the more advanced FREDders usually, here's a little test to show exactly what I mean.
When-argument
-any-of
--Ship 1
--Ship 2
--Ship 3
-true
-modify-variable
--StringVariableName
--<Argument>
-self-destruct
--StringVariableName
Which ship blows up?
Normal builds will blow up Ship 3 because they loop through the modify variable SEXP 3 times and then move on. This build will modify the variable to Ship 1, blow it up and then modify the variable to Ship 2 and then Ship 3.
http://fs2downloads.com/Misc-Downloads/Builds/Mod_Table_SEXP_Build.7z
EDIT : At the moment, mod.tbl only contains a couple of features but the basic idea is to make it the place for all those settings you set once for a mod and then never want to change again.