I'm considering buying a trailer. I'm familiar with BoBs and their reputation for getting the job done. However, I'd like to look at two wheeled trailers as well. I'm looking into Burley Trailers. I seem to remember reading somewhere about axle problems with the Burley? I don't remember if this was just an isolated problem or a problem with the brand. Can anyone tell me how durable the Burley's are and if there are any known problems with them?