Conflicts with Taxonomy Access Control

maybe http://drupalmodules.com/module/utility to adjust weight?

No, just lower the priority of CA (under Advanced).

Install Devel Node Access (from Devel module) to see what you're doing.

Adjusting module weight didn't help me. This is because hook_node_grants loads all grant rules, regardless of module order.

Apparently Drupal 6 core cannot handle multiple node_access modules. There is a contributed module to get around this: http://drupal.org/project/module_grants

Installing Module Grants allowed me to use Content Access and TAC-Lite together and seems to be the best solution.

Apparently Drupal 6 core cannot handle multiple node_access modules.

You have obviously not installed DNA (#2 above) and you don't understand how node access works. It's fine if you found a way to make your site do what you want, but please don't go around and spread untruths.

Module weight does not matter for node access. What counts is the priority of the grants, and priority influences hook_node_access_records(), not hook_node_grants().

Apologies, that was a poor choice of words. What I meant is that using multiple node access modules can cause unexpected issues (e.g. http://www.advomatic.com/blogs/marco-carbone/using-multiple-node-access-...). The Drupal 6 core issue I was looking at was #309007: Add drupal_alter() after hook_node_access_records() (AND vs OR between grants)