Originally Posted by jonmanjiro
I had a similar problem with a Nikon S2. Turned out to be related to half pressing the shutter button but not taking the shot. It triggered something inside the camera that made the camera act like a shot had been taken even though the shutter had not moved, and you had to wind on the film to reset the shutter, resulting in a blank frame. Making a conscious effort to not ride the shutter button with my finger except when actually taking a shot solved the issue. Though of course a CLA is the more permanent solution.
Seconding what Jon says here. Did you hear the shutter firing in those blank frames?
I've had Rolleiflexes, Contax IIs (the reverse actually, the shutter will fire but it won't let you wind until you fully drive the shutter button home again) and a Nikon S3 with this issue.
It stems from the fact that there are usually two mechanisms in these cameras, one for unlocking the wind mechanism and one for firing the shutter. The trigger point is usually set to be at the identical detent during manufacture/CLA, but of course over time it can go out of alignment and one thing happens before the other.