I think this was done on purpose. I had the same problem and I found the solution in some release notes.
To fix, put a ^ in front of the service_name in the .ncfg file. You will get the precise matches you want.
Example:
define ngraph{
service_name ^Current Load
...
Cheers,
James.
2009-01-12 04:48:07 UTC in NagiosGrapher
