Email module installing along with profile - gets content.module location wrong

If I install the CCK email module and core CCK using an installation profile, then email can't find a core CCK file:

Warning: include_once(/content.module) [function.include-once]: failed to open stream: No such file or directory in /home/jp/websites/drupal_6/profiles/qll/modules/email/email.install on line 5

Warning: include_once() [function.include]: Failed opening '/content.module' for inclusion (include_path='.:/usr/share/php:/usr/share/pear') in /home/jp/websites/drupal_6/profiles/qll/modules/email/email.install on line 5

These warnings prevents page headers from being changed and spoil the profile installation - I get lots of white screens with just those above errors on (and some "can't modify header" errors).

However, if I fudge a call to module_enable(array('email')) in HOOK_profile_tasks i.e. at the end of the profile installation, then everything works fine.