Hi, Actually I'm not opening a file / an image yet. (your new title isn't accurate there for) The thing I do is _browse_ for a file. Let me explain the steps.
1. Start Paint
2. Click File - Open. Paint opens a dialogbox where I can browse for a file. (I noticed that the default location that shows is the location where the last image I worked with is. For this error to occur make sure the dialogbox does not open with My Documents - My Pictures but with My Desktop). Paint displays the Open dialogbox like this http://www.jonkers.net/audio/bug2.jpg
3. Now click on My Documents on the left hand navigation (from top to bottom: My Recent Documents, Desktop, My Documents, My computer, My network)
4. Error like the one in my first post occurs. Paint does not crash but is simply frozen. I have to end the program by closing it from the task manager.
Ps: although this is my first post on this forum I enjoyed using Paint.Net from the early 2.x version. I also used almost every beta / RC prior to installing the final 3.0 version today. Never had any problems with it.