This happens consistently, to the point of me having to create files in windows explorer and then open them in the IDE.

Steps to reproduce:
Map a network drive on windows 7.
Create a new PHP project.
Point the source folder at a folder within that network drive (mine is two folders deep - sandboxes\projectname).
Point the project folder at the normal Documents\NetBeansProjects\projectname.
Open the project so that the 'source files' folder is viewable.
Right click on the 'source files' and create a new file (doesn't seem to matter what kind).
Type in any name for the file, then hit 'create'.
At this point, the IDE appears to freeze with the 'busy' icon. You can move the window around, but clicking on the close (X) or any other buttons seems to do nothing.
Bring up the task manager and kill netbeans.
Re-open netbeans and the file is there.

The times on the desktop and server are within a few seconds of each other. I'm running windows 7 64 bit. This also happened with NB7.0.1. I've tried using java 1.7 and 1.6u29.