Strange issue with Search Unleashed plugin

Hi everyone. I know this isn’t a support area for plugins, but was wondering if anyone has had a similar issue while using the Search Unleashed plugin and what they might of done to fix it.

For some reason, a few different searches people type in our search box on our site returns coded responses.

See this search here for creating a print version of a wordpress post.

We’re using the Super-Cache plugin.

Meanwhile, other searches work just fine.

Anyone else had an issue like this?

Thanks