In SharePoint Designer, I'm trying to connect to an external RSS Feed:
news.google.com/news

When I click on "Show Data" in the Data Source Library, I receive the error "The
server returned a non-specific error when trying to get data from the data
source. Check the format and content of your query and try again. If the problem
persists, contact the server administrator."

I've read the KB article associated with this error
(http://support.microsoft.com/kb/923173), but I don't think the proxy is the
problem (read on).

When I try to connect to an external web service
(services.aonaware.com/DictService/DictService.asmx for example), I can
specify the address and it brings back the list of methods (which tells me it's
not a proxy issue, since it's connecting to the external source wsdl just fine).
It allows me to select the Define method and put in a string parameter. When I
click on Show Data, I get the same error as above.

However, I am able to connect to RSS and web services on our internal network,
both in and outside of SharePoint.

Any ideas on what I should look into?

Also, if the above is working just fine for you, could you reply with the
SharePoint Designer build number you're using? I've noticed a couple different
builds (both RTM) out there, so I'm curious if the problem is related to the
build or not. I'm using build 12.0.4518.1014.