Haven't had problems with ff/rew buttons either since receiving S118, but I briefly experienced a somewhat similar issue last night. My channel up/down buttons stopped working when tuned to a specific channel, but would work just fine to scroll up and down within the guide. Then, an hour later, for no particular reason (didn't reboot or anything) the buttons started changing channels up and down again. I am using a Harmony universal remote and normally I would have blamed the remote for that hiccup, but now I am not so sure. If it happens again, I guess I'll have to pull out the original clicker and see what happens. BB@H continues working beautifully though.
I have had original remote issues before this to help solve this I turned off my HDTV Ambient Light Sensor,my remote antenna in back was straight up,I pushed the angle it was in back a little and that seem to help the erratic remote issues I was having.It almost seems like the original remote goes a little crazy during logo updating times and guide updating times,that's just my opinion.
But these type of remotes are subject to interference from different sources.I also have a Logitech Harmony 300i I use also if the original remote seems alittle crazy when I am trying to scroll through the guide,so who knows, to me it's a work in progress to try and find solutions to my issues,but I still like my 922/wMT2 very much and even more now with Blockbuster@Home.