DNS errors

I am currently touring the UK and staying at B&B's and using their free WiFi.
I am repeatedly getting the following errors at SOME places but not everytime.

Oops! This link appears broken.
DNS error occurred. Server cannot be found.

I can be surfing the internet click on a link and it works and the next time it doesn't and I get this error. Also each time I use tripadvisor.com to enter an appraisal of a place I have been the first time I do it everything works ok but if I try and create another appraisal I seem to get the error.

Is this caused by a firewall maybe the firewall used by the B&B I am staying at or is there a way around getting this annoying error?
It is particularly annoying as it sometimes happens after I have spent some time typing in a report and then I have lost what I typed in.

 

you didn't say, but I'm presuming you're using a laptop. If so, then, if possible, try changing your dns server settings and use google's dns servers: http://code.google.com/speed/public-dns/

or even openDNS: http://www.opendns.com/

or even comodo's secured dns: http://www.comodo.com/secure-dns/