Post Brake Bleed Problem?

[C4 Pazzo]

I bled my brakes and clutch last night with the Motiv bleeder and ATE Super Blue. All seemed fine when I drove it last night. This morning on start up, I get a short whirring/grinding sound from the rear immediately after engine starts. Then car seems to run fine. Clutch is smooth and firm. Brakes seem fine, perhaps a tad softer than before. Note that the old fluid was clear; must have been changed just prior to my purchasing it 3,000 miles ago.

Could this be related to the brake bleed, or just a coincidence? Any ideas? Next steps? TIA.

Car is a 2000 C4 Cab.

[C4 Pazzo]

Update

Started the car this afternoon without incident. I did notice that my seat was slightly further back than normal. I suppose its possible that I did not have the clutch pedal fully depressed, but I could not recreate the problem. I hope that's a good thing.