Hmmm...interesting how do you know it's on permanently? Ha ha ha, cos it may seem like that every time you open the boot door! Just kidding, don't think you would be that stupid!
Anyway, yeah, back on topic, the light could be on because the boot thinks it's open as the connections to the boot lock have corroded due to water ingress due to the hose leak. This happened to me but the boot open light on the dash was also illuminated. I'll try and find a link to the thread, sure it wasn't long ago.
Ah, found it, not too hard...have a butchers at the below...
http://www.tigerstyle.co.uk/poloforum/v ... hp?t=17511