Ok, I looked at the negative strip. The band clearly shows at the top of that frame, but it is confined only to that frame, does not extend beyond the image border, does not extend to the sprocket areas. The affected photo is the fourth one in on the roll. No other frames of the 36 on the roll are affected.
While I suspect a light leak of some sort, having posted sample photos on other websites have garnered responses that suggest something other than a light leak, especially because the problem extends between three different cameras.
A link to my photos (having been lightly edited in PSCC) is posted below. My half-hearted attempt to clone out the offending band will be evident (I'll go back and re-do it to make a better end product). None of the other photos in the group were affected in this way.
The film was Kodak 400 something or other (I no longer have the box or canister), but I have experienced this problem using Ektar 100. I'm currently into roll #6 on a brick with an expiration of 2/17. I shot a roll following the Kodak 400 and none of the images exhibited this problem. Ektar images on which I did find this issue were shot prior to expiration, so, go figure.
I generally just crop out the affected portion of the frame, but chose not to crop this particular image of my son with his bike.
Have a look at the following link. Glad to have any opinions or suggestions.
As to switching to digital, well, I have a DSLR but often opt to shoot film because I enjoy that medium. My film is stored in my refrigerator, and, while I didn't check for the expiration date on the "Kodak 24", none of my film is all that old. None of it has been through an airport scanner, and, hopefully, my house is relatively free from radiation.
Thanks. I appreciate all the replies here.
Caruso
https://drive.google.com/open?id=0BwTp9qz3IiX4eHhhOHdMUEVQMTg