brake warning light worry?

[ZZracing@aol.com]

Problem: my 90 20V Q brake warning light briefly flashes when the car is at
idle and I touch the brake.  Also, on very heavy breaking from high speed,
the light flashes briefly as well, but does not stay on during the rest of
the braking period.  Brakes have been recently bled (and, again, today), and
are firm and effective;  hydraulic fluid changed one week ago.
What is the problem?  Is this a warning of some impending disaster, or what?
 
I'm going to Lime Rock on August 17th - 19th, so lister assistance will be
very much appreciated.
Thank you.
Dave Zube, Vestal, NY
1990 9020VQ