I am having a similar issue. I have a double sink, garbage disposal and dishwasher all hooked up. The left side is disposal and further left is the dishwasher. I have ripped apart the trap, snaked it, pulled the dishwasher line, cleared it- reassembled everything and STILL is backed up. There is water in the bottom of the dishwasher. I am simply stuck.
I have snaked the trap out to at least 8-9 feet and used a plunger, some Liquid Lightning and am getting quite frustrated. So, I am sitting here with the trap open, all kinds of crap on the kitchen floor and frantically searching these various forums to see if anyone else out there has had a similar issue and may know anything helpoful that I am missing..
PLEASE help!!

Thanks for any in advance '-)

Hi PartherFan and welcome to The Plumbing Page at AMHD.com. You're responding to a 5 year old dead threads so I gave you one of your own. Please check the date before you post. Thanks
If you've gone up in the wall and run out 8 feet of snake you've cleared the horizontal drain line. Your clog is downstream from that and can only be reached from the kitchen roof vent. Run out enough snake to reach the base and 15 more feet. Good luck Tom

Thanks Tom aka Speedball! I was afraid that this is indeed indicative of a more serious issue than just running a snake through the trap. :(
Ugggh... guess I got to go find a ladder.
This may sound asinine- but which one is the roof vent? I don't want to snake the wrong one...

The kitchen roof vent will be the vent closest to the kitchen window. Good luck, Tom