pppoole,
Sorry for the delayed response, the export to image feature was unintentionally hidden. Go to Window > Preferences > General > Capabilities and select the Advanced button. Expand “MyEclipse Standard Tools” group and look for the “UML2 Extras (Leave off)” item. It will be unchecked, please check it and click OK. You should now see an “Export to file” action in your diagrams context menu which you can use to export.
We are currently working on improving the image export capability, I recommend you use PNG to export the image. Sorry for the inconvenience caused.