v6.3 performance

I notice that the regression test performance seems to have decreased
sometime between 980223 and 980301. I was seeing ~2:30 elapsed time for
the last few weeks, and am now seeing ~3:00. Anyone else notice this?
Might it be due to a bug fix? Inquiring minds want to know. I haven't
looked at it very carefully, so could just be imagining things. I think
it is still substantially faster than v6.2.1...