[Plugin: Amazon Reloaded for WordPress] WP 3.0.1 Error – plugin generated 2 characters

Hi,
Thank you for this great plugin! I’ve upgraded to WP 3.0.1 and when I activated, I got this message:

“The plugin generated 2 characters of unexpected output during activation. If you notice “headers already sent” messages, problems with syndication feeds or other issues, try deactivating or removing this plugin.”

I noticed this with a few other plugins that are not yet 3.0.1. Any ideas?