Your camera chamber is contaminated with clouds of developer dust? Hmm.
Originally Posted by Michael W
... OR ... Check very carefully any areas of the film outside of the images that are a little gray or a lot gray but not black. For example if the leader black shades to gray over the space of a few millimeters, check there very carefully to see if there are spots. And check any pressure streaks or crimp fog or light fog and check at the edges of the numbers and edge markings.
If the dots are not in any unexposed areas, then it is very localized over development of silver.
Are there clouds of developer dust in the darkroom air? Unlikely.
Check the developer to see if it is perfectly clear or if there is sediment that gets stirred up or specks that are suspended almost colloidally. Also, check the developer after it is fully diluted, too.