the problem is not the --debug or --nodeamon switches.
The second versions also ommits the --capability switch (and its argument).
Apperantly the capabilitties are needed by pc-suite. I guess it tells pc-suit all the relevant info about your n900 (serial number, software version etc. )

Just try to run the /usr/bin/gen-obex-capability.sh script from an x-terminal and see for yourself what info will be passed