Phantom power problem with Paia TMP

[geoff004]

I just finished building the Paia tube mic pre with all the Tape Op mods.
I haven't yet compared it to my Great Rivers so I can't give a good description of the sound of the thing.
It seems to work fine except for one thing - the phantom power takes maybe 8 seconds to come up to full power and about 30 seconds to full discharge, but only on the second channel. I measured these ramps with my DMM so I actually know what I'm seeing - besides the fact that the light on the front takes some time to fade out.

At this point I've had the thing back apart and have checked all the connections and polarities of components. The only other thing I wonder about is the 4049 CMOS hex inverter, which I've found through other projects can be very sensitive.
Any ideas?
Should I even worry about it?