Route generator using incorrect host

Hi there,

Two times in the last three months I've had Rails start serving up some links as <another site>.com/page rather than The are sites are completely unrelated to my site, and I have no idea why it did it. The first time it occured, the other site was The second time it was Sadly I can't remember how I resolved it the first time, and the second time it went away after I deployed some recent updates I'd made.

Any any know why this would happen, or what might cause it? Perhaps even some tests I can run? I'm not even sure how to reproduce it at this stage.