Strat Stringbreaker --Help!

The easiest fix is to replace the saddles. A permanent fix would be to replace them with Graphtech saddles. I replaced the saddles on mine (with regular saddles) years ago. When the D string started breaking at the saddle last year I sanded the saddle with some fine sandpaper and it is fine. When I have that problem again I will spring for the Graphtechs.

So I brought my new (1988) MIJ Strat to practice tonight...by the end of the practice I'd broken three strings

Could you describe your picking style? For example, do you play with a heavy hand, hard picks, and heavy palm muting? Do you strum gently with a light pick?

The saddles aren't the problem. String breakage is occurring where the string breaks across the bridgeplate. Remove bridge, take to a machine shop, ask them to round over the string holes. That should fix it.

You'll need to take special care if you don't want to make the problem worse. What is needed is a rounded profile without any irregularities. The likelihood of getting an uneven profile is pretty good if you DIY with a Dremel. I read a column by Dan Erlewine in a GP issue many moons ago, in which he describes a round over bit that machine shops use for this purpose. I suppose if you take the break off in tiny increments, that might get you

Yep, someone else pointed that out to me. I also found this site: http://www.guitaristonly.com/

Guy selling a stuff called 'Nut Sauce'...also sells 'string sleeves' (although he suggests that you can just use cable insulation too).

I found a piece of thin clear tubing, a little more rigid than cable insulation. Too thin to fit over the A and E strings but they weren't the strings that broke anyway. I put the tubes over all the others though. You can barely see it, and now the strings don't touch the metal at all.

Before that, I took my mini-drill and cleaned up the edges. Nothing to it, I just removed the notches that had been worn in over the years

Is your sustain and tone different?