hm … I had the same problem. My workaroud: Build and run the project in eclipse (then the classes are compiled). Then run a new project in netbeans 5, import the needed libraries. Copy the copiled sources in the bin folder of the netbeans projekt. Copy also the *.java files in the src folder. Build and run the project in netbeans. Now you find a runnable jar file in the dist folder of your filesystem.
Note: The libraries will be exported in an extra folder. When you copy the jar to another location, you will have to copy the folder structure as well …
Second note: Actually I’m not sitting at my developement computer. I hope, I described the workaround coorectly out of my mind …
Third note: matisse4myeclipse and netbeans work fine together!
Last note: I’m using eclipse, cause I need this environment for my projects. But you can use netbeans for this dirty trick! Of course, there are several ways to use the export function of eclipse. But I often had problems with the Manifest file. Well the dirty way using netbeans works any time!