error in bootstrap.inc when saving a node which is in a subscription channel

Env:
PHP 5.0.3
Apache 2
Mysql
Druapl 4.6
RHEL4

To Reproduce: (at least one way)
Go into a node listing for a category, click the subscribe link and create the subscription.
Create a new node in the category.

Result:
Email does get sent, although it looks rather bizzare.

User sees this error:
warning: Missing argument 2 for variable_get() in /drupalroot/includes/bootstrap.inc on line 152.
Header redirect fails and output is killed.

I have to pick a solution to go live with a project in 3 weeks and don't know enough drupal to debug this, is this going to be looked at before then?

Thanks,
Jacob