I canned some roasted red pepper spread yesterday and there appeared to be a reddish leak. I noticed it on the lid after I turned the water off to allow the jars to sit for 5 minutes. After I took the jars out, I did hear the "pop" and today I tested the seals--they were fine and I so no reddish food remnants. But I did see some small rust spots on the bands (two of them, so not just the jar in question). Any ideas? I've not seen this before when canning, so I'm concerned. But the seals are really tight.