Hello Tamas,
Please check following SAP notes:-
2044301 - Missing information in EWA: A troubleshooting guide - SM 7.1
1907383 - How to setup and troubleshoot EarlyWatch Alert reports in SAP Solution Manager 7.1
Verify your EWA configuration with following note:-
1924199 - EarlyWatch Alert Management SP10+
I hope this helps you in resolving the issue.
Regards
Anand