p bass pickup hum

I'm having a problem with getting the hum out of my friend's p bass. The split pickups are wired in parallel, not series. There is also a copper shield on the bottom of each pickup that is grounded. There are 3 terminals on the bottom of each pickup....a hot, a ground, and this third terminal is connected to the shielding on the bottom of eaxh pickup. The hum goes away when you rotate the guitar perpindicular to the amp. I rewired the guitar exactly as it was when i opened it up and also found no connection between the bridge and ground, which i corrected. I normally use the schematics on the web site <universal guitar wiring>, which have been a great reference. Their drawing shows the p bass split pickups wired in series, but I chose to follow the same wiring I found inside, as it's not my axe. My first guess is to rewire it as per the dwawing, but I thought I'd post this msgs and see if anybody has any ideas on the subject. -Don