Yeah I had the same problem on a big bungalow today, bits of it everywhere, i had to tell the lady that i'd get it off next time round when i've looked into it a bit more. One side of her house it came off teal easy, but the new side she had built i just could not budge it,.... well i did budge it, it just moved along the window but did not want to come off!! :-/
Mikey