Modules enabled or disabled automatically

?Why some modules are magically enabled and others magically disabled every morning, also, is there a list of modules I should avoid?

!There is a (short) list of modules you should avoid because of serious performance issues caused when used: Javascript Aggregator, Search 404 and Cookie Cache Bypass Advanced. Also, our running daily autonomous maintenance system enables some modules required to leverage all built-in performance enhancements: Cache (D6 only), Purge (D6 and D7), Expire (D6 and D7), Path alias cache (D6 only), RobotsTxt (D6 and D7) and FileField Nginx Progress (D6 and D7). It also disables a few modules, which should never be used on any live site hosted in the high performance system: DBlog, Syslog, Update, Localization Update, Poormanscron and Devel, plus abandoned SuperCron. Note that no modules are enabled or disabled on any site with “dev.” anywhere in the main domain name (domain aliases are not checked). Also, currently only 6.x and 7.x core based sites are automatically managed that way, while 5.x core based are excluded from this specific, automated maintenance.