I had the same problem with my 2000 Maxima.

Description:
Upon warm-start up, red oil light comes on two seconds after car is started, but will go off within a split second. This is actually suppost to be an oil pressure light, as opposed to an oil level light, although low oil can cause low oil pressure. The car functions normally, no apparent ill-effects.

Oil dipstick checks out good, I put in extra (Mobile 1 syn 5w30) for extra security and peace of mind just in case (its probably 5mm above the top line on the dipstick).

This only happens upon a warm start-up. Im leaning towards a slowly dying sending unit, but I'm wondering if anyone else has this issue?

 

Have it checked ASAP with a direct-reading pressure gauge. Do not take a chance that it may be a bad sending unit (could be). VQ35s are expensive!