Can you check to verify whether the fuse itself is getting power at the junction box? If you have a voltmeter, just take the fuse out, touch one lead to a ground/chassis and stick the other one inside the #30 (IIRC, or maybe it's #8) fuse terminals.
I had the same problem and BMW ended up replacing the junction box (luckily under warranty -- otherwise I probably would have just lived without the 12v ports!)
2008 E90 335i // Black Everything // photos
COBB tuned / QTP e-cutouts / Helix FMIC / cp-e DCI / AWE BOVs / Black M6 wheels + Toyo Proxes
(and yes, I am a girl)