Threads others viewed feature crashes

I have attached the screen shot. Also, it looks like it only crashes for http://www.coderanch.com/t/561744/Jobs/careers/top-interview-questions-asked-Architect thread. I tried other threads randomly and this feature works OK.

Also, apart from this bug, can somebody tell me how this feature is actually implemented? It does not look like plain text search.

Thank you.

Thanks for the bug report -- we're on it!

Our site uses Lucene for search. This feature is built with the help of Lucene's capability for finding similar texts.

Fixed. The threads with errors now have no more like this links. (Better than an error.) We think the problem is gone for new threads too, but do let us know if you see it again.