John,
If I were you I'd recalibrate your monitor, maybe do one at D50, and see if that works better for you. It could be that your calibration device is on the blink, possibly. You haven't mentioned what hardware/software calibration combination you are using.
Peter, While I understand what you are saying, and it may work for you, your method would drive me nuts. I always take what I see on the screen with "a pinch of salt", knowing that there will be trade off's when printing, but I prefer to have something working well on the screen before I deal with going to paper. For what it's worth though, I don't print to difficult media like canvas or matte papers, so I suffer less problems when printing.
Andrew, yes of course, although I have to say that making the choice between rendering intents is the hardest decision. A lot of the time I find there is little difference between the two, or if there is it's difficult to know which way to go. I always have a coin on hand....