Yes, the tubliss system needs to be kept at 100-110psi to keep the tire seated in the bead. The tire itself (you use a 2nd valve for this) can be run way down, at 3 psi if you want.
Because of the many large and small rocks I get to deal with, I keep my tires inflated to around 20 psi.

I've also mentioned using the bigger bikes (anything over 125kg, the weight of a fully loaded exc with long range gas tank), and I've always noticed that tires start to roll sideways on the rims during fast cornering, if the tire pressure is run to low.
It was something I noticed a lot on the 690 when I got it. Basically, theis stops the front tire biting properly and makes for a skating effect which a lot of people feel is the bike pushing into a corner. It's really not that; although to much rear sag does cause pushing...it's more to do with a lot of the tread of the tire failing to be the contact patch with the ground as its pushed well off to the wrong side of the rim. You then get a lot more sidewall making contact with the ground than you should have, so your very effectively running a semi slick tire.
I was a little reticent about voicing this until I read the 2010 690r review by Chilly White. He mentioned exactly the same thing, and the vast change in handling when he inflated the tires more than usual, so I feel a lot better about saying it.
Btw, his review is well worth reading.