No problem, just glad to be of help.

I'm adding a list of the commands I mentioned before, just so that you (and others) know what they actually do.

• apt-get update -- this is the equivalent of an application manager -> tools -> refresh list, the difference is that apt-get update updates the list even if one or more of your repositories are unavailable. The application manager doesn't.
• apt-get install package-name -- this command will install the named package, with all its dependencies resolved (additonal packages) if possible. It is the equivalent of both installing a package from the application manager as well as updating (upgrading) a package from the application manager
• apt-get install package-name -su -- the same as above, but it doesn't install/upgrade anything: -s means 'show me what you would've done', and -u means 'list what to install'.
• dpkg --purge package-name -- this command removes an installed package (application) completely, including its configuration files (there's an equivalent --remove which leaves the config files in place, in case you intend to re-install it later with your original configuration).
• apt-get clean -- this command simply removes any downloaded .deb file. They live in /var/apt/cache/archive/, but the N800/770 is configured to normally auto-delete them after actual installation. Still, if something goes wrong there may be files left over (and it could be that installing directly with apt-get install may leave files there - I haven't checked. In any case, apt-get clean is a safe command to run.)