It seems that the first
<a> tag in any piece of content being processed by your plugin (page, post, custom widget etc.) is NOT getting processed/checked for being external.
If I make a page or post where the FIRST link encountered is
<a href="http://example.com/">Link</a> , it does NOT get processed as External. However, if I add a dummy
<a></a> anywhere BEFORE that first external link, things work as they should.
I tested this in a new, clean WP 3.5.1 install with HTML5Reset theme, and only one plugin: External Links 1.31
Could you please examine? I've not noticed this bug before (I've used your great plugin for a while) but it could be that the content usually has other links first.
Thanks for your work on this plugin!!