Most systems that I've been fortunate enough to be involved in don't always list the manufacturer that will run with their motherboard, and generally say only a few different speeds. When we've had a chance to try different speeds that weren't listed, everything worked fine except once. As a previous member stated, when you go into the bios and manually set your ram speed, I've always seen just about every speed I know of and even some I hadn't seen before.
Also, if a board will run 1066,1333 and 2000, why can't it run anything in between. I'm no expert just tried a few different things and maybe those who really know will shed some light on this as I'm curious myself to find out.
Good luck, and I'm sure everything will be just fine.
