(What other Scheme systems did you find implemented SRFI 43 from scratch, by the way? The only system I know of that already boasts SRFI 43 support is Chicken, and there it's just a modification of an old version of my reference implementation.)
I was just looking at Chicken, and their implementation looked pretty different from the reference one, so I assumed that someone had just done it over. It didn't occur to me that it could be an older version.
Thanks for fixing things so fast! WillP.S. -- I was looking at the reference implementation because I wanted to wrap vector-lib up for bigloo, so maybe there'll be a second scheme which implements your SRFI soon.