If you want to warm it up a bit just put a bit of duct tape over the bottom of the rad. We used to do this on the race bikes just remember to remove it when it gets warmer.
there was a few flakes of snow as i rode in this morning (748E 2002MY) and the temp was always above 60 and got to 80 in traffic. i think below 60 i would be a little worried too. On summer days it gets to 98 and the fans cut-in. the smooth fairing on the 2002 doesn't dissipate heat as well as the earlier (used to have 2001 model). do you know what additive you have in the rad - when was it changed? and do you have the right amount? checking thermostat should be easy as well. They would be my first things to check - sounds like the sensor is OK.
I must admit I'm not sure what coolant is in the bike and when it was last changed as the bike was new, to me, in the summer. I can easily check the stat, when I have the bake with me, but not at the moment.
Like I said earlier, I had no problems with the temperature around town or at low speed. It was just the quicker I went the colder it got, to some extent.
I'll take a look at it the next time I am reunited. Should be in a couple of months. Snif.