Jeff, I think it is safe to make this assumption:(posted 8907 days ago)If you have a roll of film developed and some negatives are correctly exposed, and others are incorrectly exposed, and this exposure variation is confined to negative picture area, then you are having camera problems.
There is just NO way that the developer would affect only one well- defined negative & not portions of another.
The aperture of your lens might me sticking, or your metering might be malfunctioning.
chris