I have not had problems with the older more rectangular 100 lb Carter bags dumping on the way up. However I have had the problem with the more compact 50 lb triangular shaped bags. You need to keep just a bit of tension on the line as they go up or the smaller and less draggy bottom of the bag will try to pass the wider and much draggier top of the bag. If it succeeds, the bag can dump. A little friction on your finger spool or reel prevents any problems though.