I've found out that Dropbox is really and I mean really affecting Windows explorer performance. I'm using Windows Explorer as primary explorer in Windows. Dropbox is adding some extensions to it - some icons on folders in special Dropbox folder and also right click menu. Fact is that everything is saved on dropbox server and you have to wait till it's downloaded. But last 3 days Dropbox is overloaded and I'm experiencing Server error 500 on their website and application just says synchronizing like whole day. In that case Windows Explorer is like you have to wait a minute for directory being fully loaded - all files, images etc. And also no right click working. After disabling Dropbox and restarting my PC everything is cool. I've found out that till the Dropbox cannot reach server it is okay but after Dropbox connection is estabilished and Dropbox will being overloaded Explorer will just stop working.
I was just wondering if you guys are experiencing the same problem as me and few of my friends. And I'd like to notify Dropbox developers about it because it really annoying but I have no idea where or how to do so.