Found the problem. I poked around in the install code and found the schema for the tables. I tried to manually create the tables which died on this:

CREATE TABLE IF NOT EXISTS `jos_arisc_plugin_params` (
`ParamId` int(11) unsigned NOT NULL,
`ParamValue` text NOT NULL default ''
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

MySQL 5.1.40 did not allow a default value to be set for text/blog fields. I remove the default setting, created all the tables, and reloaded the arismartcontent plug-in.

This allowed me to load 1.8.1 without error, but the plug-in seems to have no affect. The articles just display the ari tags as if the plug was not enabled. (I confirmed that the smart content plug-in and the extensions plug-in are enabled.)

I have the ARI Data Table product installed too. Could that be a problem?

I noticed that the jos_arisc_cofig, jos_arisc_css, and jos_arisc_plugin_params tables are empty. Is that expected?

These tables are empty on fresh installation. Check that "System - ARI Smart Content" plugin is enabled and if you use a WYSIWYG editor, switch it to plain text mode before inserting plugin code. WYSIWYG editors can add extra HTML code in design mode.

Regards,
ARI Soft