It looks like the SIGPLAN class file has gotten out of sync with the paper requirements and is producing a slightly too large textblock. I just checked the template (filled out with random text) against the format checker. It fails.

In this situation, it seems wisest to go with the class file instead of

I just thought I'd pass on Stephanie's response, as she couldn't post to the list: the stated height requirement.

I've upped the format checker to a max 9.5in height to account for this discrepancy.

Hope this helps, Wouter