(Wag @ Oct. 06 2006,17:58) Always use the pressure as printed on the tire itself. When they had that big Firestone fiasco a few years ago, it came out in the courts that the tires were failing because the auto manufacturers were likely to blame because they were underinflating tires and recommending same to the consumers. Gives a smoother ride and all that jazz. That's the short version.
Regardless, the pressure printed on the sidewall of the tire is put there by the guys who make the tires and after all that court stuff, it was dertermined that yes, they know best how to inflate tires.
(Aside from that, Firestone DID have other problems with their tires which had nothing to do with tire pressure.)
It takes about 30 minutes to warm up those Bridgestones. Before that, you're riding on cold tires. Add to that cold pavement and you're hosed. That's one reason why riding in the twisties can be risky because you can go from tree-shaded pavement to sunny pavement in very short order. This is more of a problem in the morning but if you're in a tight turn going too fast, a change in asphalt temperature can throw you down.
Lastly, your suspension needs to be set so that it maximizes the contact time with the road. If it's bouncing around, you're going to "slip" in turns. I'm no suspension expert so I can't tell you how to set it but keep a close eye on it for signs of cupping. It could be low tire pressure but it could also be suspension problems. Regardless, the idea is, as before, to make sure your suspension and damping equipment in your forks are keeping you tire on the road.
If you sit on the bike and push down on the handlebars and let go all at once, it should come up and stop. No bounce. If it bounces, something is wrong.
--Wag--