I have html tidy installed and enabled via php 5.1.x. I tested the install by:
$tidy = tidy_parse_string("<B>Hello</I> How are <U> you?</B>");
And am able to get the html fixed in the results. My php install doesn't have any values for open_basedir so I'm not sure if that is the problem.
I'm also not sure what to set the "Path to HTMLTidy executable" - the default value of /usr/bin/tidy seems to throw errors:
* warning: exec() has been disabled for security reasons in /nfs/disk/data/www/virtual/webdev.ous.edu/cws/modules/import_html/coders_php_library/install-htmltidy.inc on line 87.
* HTMLTidy executable is not available. Found 'tidy' binary, but it didn't run right. /usr/bin/tidy -v failed to respond correctly