Lately, our westy has exhibited difficulty maintaining its idle in the first
minute or so of cold running.  It idles very low during this period, and if
you don't nurse it, will cut out.  (For example, if you rev the engine, then
when it comes back down it will probably die).

After 1-2 minutes, everything is perfectly peachy.  Gas mileage is still
very high.

I've tried:
swapping out the temp 2 sensor with an extra one
setting the warm idle rate to spec (850 rpms) with the adjustment screw with
the stabilizer bypassed
a new idle stabilizer (needed one anyways because the plastic tabs broke off
mine)
checking the idle switch (it clicks and functions correctly, at least engine
breaking fuel shutoff works)

Any suggestions on where to go next?

Thanks very much,
Wes