Lights On + Brakes = Trunk Opens By Itself Help!

[phlups]

Hi Everyone
Wanted to start by saying thanks to everyone for all of their help. I read these forums everyday and many of you help people everyday and don't know it. You've certainly helped me, so thank you!

As the title states, when my headlights are on and I hit the brakes, my trunk will relelase. I have an 01 X5 3.0. I've only had it since August and this is my first winter with it. It has only started happening since the winter arrived here in Toronto.
I think it happens more when it's wet outside. It doesn't happen every time though. I tired disconecting the wires that go to the licence plate lights. It turns out they were severely corroded. I thought that was somehow connected to the trunk release. I guess not because it didn't do a thing to fix it.
I've read some other articles on this problem but am unclear on what to do to fix it. Can anyone help me on what to do about this?

Thanks so much!