An update to SketchUp has been released for Windows and Mac. Build 4.0.170 allows files to be exported to version 3.x and offers several bug fixes.
The SketchUp team have responded to user demands for backwards compatibility to version 3.x by adding an exporter. Information unique to version 4.0 will be stripped from the model.
Several bugs in the 3ds exporter have been fixed in the new release as have several other miscellaneous bugs.
The update is free to version 4.0 users and can be downloaded from the SketchUp Web site.