i received my k-r in april, e-dial acted up shortly thereafter (moving it either way would result in a fast forwarding/sporadic to the highest zoom or aperture, etc and it would get stuck there). the moving it fast back and forth technique did little to help me. i sent it to pentax and had it fixed under warranty. received it from pentax repair, worked for awhile (< a month), then last month had the same issues while on vacation. i emailed pentax for what to do, send it for repair again or ask for a new body, they said "send it for repair again".
last night i went to my local home depot and picked up this contact cleaner
http://www.crcindustries.com/Catalog/images/Cleaners%20and%20Degreasers/02130.jpg
after applying the contact solution, my e-dial is working like it hasn't ever worked before ... like new!
the dial moves incrementally, step by step as it should in all modes.
note: home depot also sells a CRC degreaser, but it did not say it was safe for plastics so i bought the contact cleaner instead. also, the contact cleaner did not come with a straw for intricate spraying, so i took one off another can for this purpose. don't tell. hope this helps skeptics on the fence.