I'm happy to report this issue has been resolved with 1.37. Apparently, things are REALLY slow if you pass Unix style paths to DOMDocument::load() on a Windows system.
As for the extra-process interference... I have no idea, but adding realpath() seems to remove the need for it. -- Edward Z. Yang GnuPG: 0x869C48DA HTML Purifier <http://htmlpurifier.org> Anti-XSS Filter [[ 3FA8 E9A9 7385 B691 A6FC B3CB A933 BE7D 869C 48DA ]]