High Gears slipping under load

hippy You sure the chain isn't too long? Here's some methods for checking: http://www.parktool.com/repair/readhowto.asp?id=26

my chain looks pretty much exactly like the perfect set up on that website:

so I can't imagine its that.
There is more to that page you linked though. I'll go through it tonight when I'm not at work.

nimhbus tsomething similar happened to me...turned out one of the teeth on the front cog was bent out of shape. i would never have thought of it, but that's what it was.

Thing is they were fine before and they even 'look' fine now. Also it only really happens in the smaller cogs at the rear. It also happens in big cog front and little cog rear so that should (in theory) mean its not that.

I'm gonna loosen the gears off tonight and completely rest everything (if I'm not too tired from riding my clunker to and from work - it was actually quite a nice relaxed ride this morning. So much more comfortable to ride than my other bikes... but slower.

Again, I appreciate the help guys. Cheers.