Hopefully, a simple door lock vacuum question

[rgnprof]

I have been doing some troubleshooting, trying to isolate a slow leak. If I lock the doors after driving the car, all 4 door locks lock appropriately, and if I try and unlock them within a few minutes they will all unlock. But, if I wait a while (1/2 hour or so), then they don't unlock anymore.

I have been checking hoses with my Mityvac and have found a slow leak in the plain, yellow hose that runs from the check valve under the hood to the front driver's door (at least, I think that's where it runs). The reservoir hose holds vacuum just fine and so do the rubber door diaphragms.

What does this leak indicate?

ryan