In case you suffer from random JDownloader-Crashes and you have hs_err files in your JDownloader folder, please open them and see if they contain
lines like [awt.dll]. In those cases it can help to start JDownloader with Direct3D disabled:
Start JD with
java -jar -Xmx512m -Dsun.java2d.d3d=false JDownloader.jar
For ATI-Users, the following might help too:
In AMD Catalyst Control Center: Gaming->3D Application Settings->Anti-Aliasing-> disable "Morphological filtering"