SQL 2008 Server agent cant see perfmon counters

I am trying to create a new SQL server agent alert to capture "SQLServer:General Statistics|Processes Blocked||>|5' but it looks like alert creation GUI is not able to see any perfmon counters as in the following picture: The drop downs for Object, counter and instance are empty. I can't even create the alert using TSQL as follows: I can see these counters collecting data in perfmon. Any ideas? Thanks in advance...