It is great that NetBeans supports multiple top-level windows, but the implementation is not flexible enough, and documents don't always open where you would like them to.

In my case, I prefer to use 2 NetBeans windows as my default setup, and sometimes 3 or 4 depending on what I'm doing.  In the 2-window setup, I arrange two windows side by side, with the project, files, profiler, output window, find usage results in the left window, and the right window for all source files.  When I open additional windows, these are also for source files (so that I can do side-by-side source editing).  The problems I experience are as follows:

1.  I would like to be able to drag the source file container from the main window to a new window in a single action.  If I could do this, it would probably solve all of the other issues I have.  Instead, I am only able to drag a single source document at a time.  For example, I can drag a source document to the desktop, and this will form a new window.  Then I can drag additional source documents to the same, new window and they will be moved to that window.  Instead of this, I would like to be able to drag *all* of the documents -- the entire container -- to a new window.

2.  Because I cannot remove the source file container from the main window, the only thing I can do is to remove all documents from it, and make it as small as possible.  I have to drag the divider until it's only a few pixels tall.  This really sucks.

3.  When I double-click a source file in the project treeview, it sometimes goes to the source file container in the main window, and not in the second window.  At least, NetBeans will usually remember where I last opened a document and open it there, but sometimes it doesn't.

4.  When I drag-and-drop a file from Windows Explorer (shell) into the second window, the source file should open in a document in that same window.  Instead, it *always* opens in the main window.  This is very disorienting, and took a long time to figure out, the first time it happened.  Even after continuous use, it always takes me a second or two to remember to look in the (minimized, few-pixels-tall) source document container in the main window.

5.  When all of the source files in the second window belong to a single project (or project group) and I close the project, the source files are all closed (proper behavior), but the window is also closed and lost forever.  If I reopen the project, all of the files go into the (minimized, few-pixels-tall) source document container in the main window.  This is *extremely* annoying and tiresome, because I then have to recreate the second window and then drag each source file one-by-one into the new window.  For 5 documents it's annoying, for 10 documents or more it's completely out of the question.  Extreme frustration.  At least, could we change the behavior (or have a configurable option) to leave a secondary source window open even after all documents have been closed?