Since Paul Jones posted his shot I am also sharing mine to compare the local conditions variance. I had 4.5/5 seeing for most of the time from 0930 - 1045UTC on 20121025. The really neat thing is that I didn't notice Europa onscreen, live display until it neared exit of the disk. I was nearly blending into the disk of Jupiter then it grew VERY bright and contrasty. Perhaps moving from center of transit near the brightness of the center of the disk towards the dark limb?
PS, this is a rough 1st pass at processing, my scope is only 1.5years old and this is only my 2nd Jupiter opposition, and working with good data is rare!
PPS, I wrote some scripts to batch stack in AS2 and batch sharpen in AstraImage, part of my one script to rule them all, v10 processing routine. It's working well so far!