As you probably know there are some issues with the Enterprise-Manager, today i came around some really ugly things. In my Test-Installation i am using Enterprise-Manager on Windows Server, and tried to write a RMAN-Job. When trying to start these jobs i get: "No rman found in c:\oracle\product\11.1.0/bin". In this error-messages there are several issues there is one slash "/" instead of a backslash "\" and the directory is NOT my Oracle-Home.
I installed the newest version of the agent, but it did not work either. So i tried a workaround. I simply wrote a batch-script that starts RMAN and a RMAN-Script with "rman @testscript.txt" in the script i use connect target to connect to the correct instance (not the best way but it works).
Next Error-Message: "Message file RMAN<>.msb not found". This time the ORACLE_HOME variable was not set. ORACLE_HOME on Windows? Isn't that a linux/unix-thing? YES.... normally in windows just the PATH-Variable is rewritten wenn changing Oracle-Homes, but in this case the management seems to rely that there is such an variable. So i simply added a SET ORACLE_HOME=C:\oracle\product\11.1.0\db_1 in my batch-script.
Now it seems to work properly 
, i hope they fixed it in the new Enterprise-Manager version already....