Yes, the N900 build in GPS is supported through the standard method (liblocation), so it should work. You can check a few things:

• is the GPS turned on ?
• are you running modRana the right way ?
  • modRana needs to know that it is running on a N900 to turn on the liblocation support
  • this is taken care of by this script: /usr/bin/modrana (this is what you run, when you type "modrana" to the command line)
• was there installation flawless (no error messages during install)?

Well, I can say thats really pretty weird. Well, there are a few more things you can try:

• make sure you are root when installing/removing/purging modrana from the command line
• purge modrana
  Code:

  apt-get remove --purge modrana

  this should completely remove modrana from your system
• after purging try to reinstall with the app mamanger
• if this fails, purge again and try to install from the command line
  Code:

  apt-get install modrana

  this really should not install cloudgps
• if launching modrana using the desktop icon fails, try tu run it from the command line (as a user) by typing:
  Code:

  modrana

• if you get some (copypastable) errors, when running or installing, please PM them to me

Thanks !

Well, it can run even with 777, it doesn't break anything in the app.
But following the standard packaging practices, only what needs to be writable should be writable and so on. Therefore I set the permissions for the code to be read only and configs/tracklogs/cache/etc to be writable. So either I set wrong permissions somewhere or the installation failed during the postinst script, which is when the permissions are set.