Usersettings.con is a stock file (not folder) that is installed with BF2142, you can find it in Battlefield 2142/mods/bf2142 for normal BF2142 and mods/clanmod for clanmod IIRC.
Some people 'tweak' their usersettings.con file to improve hit registration, although it's never been proven that this actually works.
Because some server admins consider this an unfair advantage, they run MD5-checks for stock files, including usersettings.con
The problem with this is that it's very unreliable, as there are many more factors that can cause the usersettings.con file to be altered; it's possible that the file is different on the deluxe version of the game.
Basically, if your version of usersettings.con differs from what the server running these checks considers 'normal', you will get kicked.
As this only happens on a handful of servers that run these extra checks, all I can recommend is contacting the server admins and talking to them about it; updates often get released for this check to reduce the chances of an innocent player being kicked.
This is exactly why PBB does not run MD5-checks on these stock files ;)