PubMed connection - ISA Server requires authorization?

Dear All,

This might be a silly question, but I’m getting an error message when trying to connect to PubMed: “Proxy authentication required (The ISA Server requires authorization to fulfill the request. Access to the web proxy filter is denied.) Negotiate”

I’m sitting behind a company proxy and firewall and this problem never occurred before with any previous versions of EndNote I used (currently using X1). Also, I’m not getting this error message when trying to connect to other web based connections (e.g. WOS), so it dose not seem to be a problem of our proxy setting.

Any clues?