OK, this section if for "Moving to Finland", but this topic is about "Moving OUT of Finland"

I've been living in Finland since year 2000, working and having a permanent residence. Recently, I got an expat contract to work outside EU-zone for couple of years.
According to the immigration law, after two years of residing abroad continuously, my permit will be canceled:
http://www.poliisi.fi/poliisi/home.nsf/ ... F40033C9B5
My questions are:
1) How would UVI know that I am residing abroad
2) If the residence permit is cancelled, then what about the permanent visa sticker in my passport. How would they cancel it? I mean that the visa sticker is valid as far as my passport is valid; in this case I can visit Finland at any time, even though the residence permit is cancelled. Right??
Your advice will be highly appreciated!