Running tilecreator in scratchbox does not work on the armel target (Qt programs loading .jpg files via QImage/QImageReader segfault in scratchbox). Therefore tiles cannot be created from srtm.jpg, which leads to a segfault on the device when activating maps using srtm data on the N900. As a workaround, the data files (which are architecture independent) can be copied from a different build.
Maemo devices have uncommon partition layouts and sizes. In particular, space on / is quite limited, /home and /opt have more and /home/user/MyDocs plenty. For this reason we install marble in /opt/marble and use /home/user/MyDocs/.local/share/marble to store cached data.