You have updates available on another account I received this Mac as a gift. Everything worked fine, now in the App Store the default applications GarageBand, iMovie and iPhoto refuse to update, since it asks for the Apple ID of the previous owner.

So this is not like a bug other people perceive, who ever had only one AppleID its really changed ownership. When we did that, I also created a Account for me with Admin escalation, and deleted the account of the previous owner to safe any personal data.

So now how can I update these default apps that came bundled with the device? Can I deinstall'em and reinstall with my AppleID?

Its not like I want any Apps that the previous owner bought (all deinstalled and installed my ones), only those that are tied to the device.
I had a similar issue when I first got my Mac.  The first thing you want to try is going to the "Purchased" tab in the App Store and seeing if it gives you the option to "accept" the iLife apps at the top of that page.  If not, then you should contact the App Store support team using this website: http://www.apple.com/support/mac/app-store/contact/ .  They will most likely email you back asking for your serial number to confirm that you are eligible for the apps.  For me, they validated my serial, verified that I was eligible for the apps, and issued me redemption codes for all of the iLife apps.  After that, no problems.  If they issue you codes, make sure you uninstall the three iLife apps through Launchpad before using the codes and redownloading them.