On my ride to/from work today I nearly died - the grin on my face was soooo big it was like a ram-air scoop and I almost couldn't breathe out! It was like riding a completely different scoot - I hadn't realized that I was actually having the problem at all speeds and that the eratic wandering in the truck ruts wasn't normal and the bike didn't have to feel just slightly unstable when cornering at near highway speed! Everything felt so solid today that I even scraped the boards once without worrying about it.
I don't know whether it was the higher torque I used on the brace, or the tightening sequence for the entire forks that made the difference, or the combination of the two. I do know that the bike is a lot more fun to ride when the wheel and the bars point the same direction ALL the time instead of 'just on average'.
Thanks all for the help. OldWrench - that was a fantastic offer! N2ppn - I had checked the alignment using 2 strings from the back tire to the front and it looked pretty close to me