2x drop not entirely increasing drop rate for area bosses?

Ick, good thing to know I'm no the only one. I'll blame my poor 2x drops then on plain bad luck.

One time, I decided to get lots of 2x drop. A 30 day 4 hour drop to go with my 30 day 2x exp. (Same times, so I got items while training.)

I trained at spiders for almost 20 levels. The only ilbi I saw drop was from a random fire mage that came in and decided he could take the bottom. Out of about... 20-22 days (I spent time at voodoos first to max BoT.) that was the result. Got barely any scrolls, and they weren't good. Mostly got gear. And only rare ones was 2-3 black rabs. Yay?

My gf who got 2x exp only, and did all 30 days at wolf spiders got 6 ilbis in those days.

Idk if it's just my horrible luck, (I've had it my whole life.) but I'm hoping it's not and that there's just some mistake. I hate it when money goes to waste too...