Best way to clean Blender? Blender recently started to act really weird, one of the most frustrating things is that Blender History states stopped working. I am looking for some advice on how to clean things that might be messing up my Blender. 

Also I would really appreciate some help on how to make it as easy as possible to reinstall a new version of blender and transfer my old settings. I am using Blender 2.75a the official version today. I know that I can transfer the old settings after I install a new version of Blender but I am not sure if that's really good if some old script/settings are messing up some things how can I find where the problem is?
Here are some things to try :


first make a copy of your the config file.
restore default settings.
disable the user addons ( the ones you installed ).
enable the console and read the log for any warnings or errors ( addons could cause that ).
install fresh copy and don't transfer the settings ( in case the problem is not from your settings ) .