I get a problem

[Upoessiond1938]

From time to time, there is a noticeable delay (2-3 seconds) before the folder you just clicked on opens.
This doesn't happen all the time but fairly often.
It is not related to the size of the folder nor is it related to the amount of files or folders in this folder.
It's a bit annoying.

BTW: The bookmarks bar and the programs bar don't work either, but I don't really care about that.

The version I use is the newest 64Bit version on Windows 7 64Bit.