Error with timeline when project panel is active

I am not native speaker, so sorry for my english. I have unordinary problem. My timeline doesnt work, when i have opened, and active "project panel" or any bin from current project. Everything works fine when i swich to "effect panel" or any other one. It is possible to work with that issue but its very annoying. Even if im creating new project it works, till I "copy-paste" all items from previous one. It worked great first few hours, bug appeard suddenly. Do you know how can i fix this.