Okay, I found a way...
Basically the Frontrow app itself does not need to be replaced. Apparently it is the file in the CoreServices that matters.
To find this file: download the link I have found earlier: http://www.versiontracker.com/dyn/moreinfo/macosx/28431
Mount it, right click on FrontRowUpdate1.3.1.pkg and select "show package content"
Then go to Archive.pax.gz in the contents folder and unarchive. This will show up on your desktop as the folder Archive. Then go into this folder to Archive/System/Library/Coreservices/Front Row. That's the file you need! Copy this to System/library/CoreServices/
Can someone let me know if this works? Maybe it works on my system because some .plist files or preferences have been changed by the installer, which of course does not happen by just copying the file in CoreServices.
It worked to start FR, but when i went into video folder it popped "problem have occurred" and just hang. After pressing few times on menu it came out of FR. I tried again - the same thing. But music and photos work fine. I didn't try to watch dvd.