I know of at least a dozen conversions with ramped rings (including three or four of my own) that are fine. What bothers me is that there are many documented conversions with ramped rings floating around, and many websites that would suggest you just remove two rings and use your middle ring for a conversion. If this didn't work, no one would be advocating it. What bothered me about your post is that you say a ramped chain "will not work". C'mon. Generalized (and unsubtantiated) statements like that are dangerous and unfounded. Had you said "over the past five years I've built 5 SS bikes and I know a few others who have found ramped rings to pose a problem", that would have been fine. But, to declare a ramped ring the source of all that is evil is a bit of a stretch, especially when I know, and have had "personal experience" with many, many conversions with ramped rings.

As someone else said, the ramps are on the inside of the chainring and only affect shifting. If you chain was coming off, something else was going on. Either the ring wasn't straight, some teeth were bent, it was worn out, you were using a BMX chain on a 8/9spd ring, etc.