here's some research i did on the issue. i was curious too.
from the sansamp site "For studio and live applications, SansAmp Bass Driver DI is engineered with three outputs: an effected XLR, and effected 1/4", and a parallel, uneffected 1/4". The footswitch activates the Tube Amplifier Emulation circuitry. Disengaging the circuitry enables you to use SansAmp Bass Driver DI as a standard active transparent direct box."
here is something from another site...
"I recently bought a sansamp bass driver and they certainly are nice. It will boost the level of you bass a lot and allow you to eq it. It also ads its own particular sound. In live situations, you can dial in a tone that you like and then take that around with you wherever you go. It depends what you intend using it for really. A couple things worth noting... if you are using an active bass and sending it thru the sansamp and into an audio interface (e.g. for recording), you may well end up with a signal that is too hot! If you plug a budget bass into the sansamp, it can really enhance the sound. But if you are already getting a decent bass sound/level, this pedal may not bring you anything you cant already get with a little hardware/sofware eq."
so if i read those two together, it seems that an active di + an active bass = too hot of a signal. have you tried a passive d.i. with your urge?