When compiling invalid objects I would like to work in another window. But compiling totaly freezes PL/SQL Developer. When the compiling is done then Developer unfreezes and I can continue with work.

The same sometimes happens when running programs, but not always. Sometimes I am able to run slow select in one window and switch to another window where i can continue with work.

Does anyone have a solution? My co-worker usually has two Developers running, but I don't think this is a good solution.

The Compile Invalid Objects tool does indeed not do its work in the background. I have added this to the list of enhancement requests.

Programs execution always occurs in the background though. This should never cause any freeze.