I haven't found any other users with the same problem, so I probably do something wrong.
When I wanted to apply a Warp Stabilizer effect to two clips in a sequence I got the message: "Warp Stabilizer and Time remapping can't be used on the same clip."
And indeed the clip had Speed keyframes in there. I don't want to do any time or speed adjustments, so I deleted the keyframes, and re-analyzed the Warp Stab successfully. All normal so far.
But!, When I close and re-open the project the deleted keyframes are back and the Warning-banner returns! In fact all of my clips apprear to have time-remapping keyframes.
A few other clips have the warp-stab applied and although they also have similar keyframes Premiere doesn't seem to be bothered by it.
Premiere Pro CC 8.0.1
In fact clips mentioned above are segments of a multicam clip made of nesed sequences. That might be relevant alhough direct clips also recreate the timeremapping keyframes.