Extra content being inserted using Active Records

[eluser]WanWizard[/eluser]
The AR code doesn't insert records twice, so something else must be causing this.

Activate logging by setting the log_threshold in config/config.php to 4.
Delete or empty any logfiles that are present, perform the action again, and check your CI logs. Anything unusual? Redirects or reloads of the page?

Another test: directly after the insert, add a 'die("stop here");' to make sure your script doesn't continue. Do you still have two records inserted?