I just started using carrot2 directly today (I have previous experience using it as part of @note2).
I am able to search the web and Wikipedia through either http://search.carrot2.org or the workbench application.
When searching the pubmed source, I get the following errors:
java.net.SocketTimeoutException: Read timed out
org.apache.http.conn.ConnectTimeoutException: Connect to eutils.ncbi.nlm.nih.gov/eutils.ncbi.nlm.nih.gov/130.14.29.110 timed out
Could they be transient or version dependent? Is anyone else successfully searching and clustering pubmed records with carrot2?