The C3000 has a larger screen resolution (640x480) than the older models. Older applications designed for those models by default start in portrait mode (because that is their default mode). The C3000 supports both portrait and landscape mode. The clam shell design detects when the screen is rotated and automatically re-adjusts the orientation. However, it also detects that these older applications were build for portrait mode and also automatically switches to portrait mode when those applications are run.
To change this behaviour, tab on the application icon and hold the stylus there for a few seconds and a properties screen will appear. Untick the option "Display with magnified screen". (This needs to be done for each application)
Alternatively you can add the following line to the appropriate .desktop file located under /home/QtPalmtop/apps