Hi Kath,
I think you may have encountered a website glitch or somesuch, it seems to work ok for me.
Please retry just entering name "Thomas Palmer" from this link; http://ww3.gloucestershire.gov.uk/genealogy/Search.aspx

This will hopefully give you a list of 25+ men, your Thomas is halfway down the first page; Year "1751", Parish "Longney" etc. Did you see this when you tried ?.

Click the "ordering information" hyperlink at right hand side and hopefully it will work ok.

Hope this helps, Jeff