creepy tech-savvy stalkers

Dear tech-savvy flist:

So, say someone has somehow hacked into my Gmail account even though I've continually changed the password after I first suspected this person to have gotten ahold of it. Said person is keeping a low profile and not doing anything but, you know, invading my privacy and reading my emails and being a creepy stalker but - how would said person have managed to continue to get into my account after numerous password changes?

This was first noticed because, when you're logged into Gmail, it tells you at the bottom of the page by your storage stats if you're logged into this account from another IP. I looked up the IP and I know exactly who this person is but...how on earth did said person hack into my account? And how can I block this person from managing to get into my account in the future?

Please help.

Disturbed (but knowing at least who she is dealing with),
Mei

ETA: Never mind. Figured it out.