Mod_gzip bug and WebDAV?

I’m seeing an odd intermittent bug with my WebDAV-enabled directory – I try to download a large HTML file stored there, and the end of the page becomes hopelessly garbled. This happens with both IE and Firefox as the browser.

It looks like gzip decompression has gone astray on this file.

Has anyone else seen this problem? Does anyone know how to turn off mod_gzip for WebDAV directories?