Scanning family slides

My grandfather has about 40 trays of slides that I've decided to scan. To do the job I bought the Nikon Coolscan 5000 with the SF-210 slide feeder attachment.



It works fairly well, other than the occasional jam when feeding old cardboard mount slides. What happens is the little raised ridges on the feeder will get caught on the window of the next slide exactly like this post describes:

http://forums.dpreview.com/forums/read.asp?forum=1007&message=15300370

Although I am not sure I want to hack at my slide feeder like that guy did.