Hi,
I had a similar problem recently. In my case the jobs were also scheduled, but could not be executed. In my case, I saw a lot of Jobs in "ERROR" state in the Jobs tab of the Java Scheduler. Maybe you can find out more details, when looking at the failed jobs. Did you already have a look at the "Log Viewer"? You should see more details there, why your jobs run into "ERROR" state.
In my case I also saw several jobs in the "STARTING" state which could not be executed. They seemed to block any new job. Finaly it turned out that there was some kind of inconsistency between the local UME database and the LDAP directory. UME pointed to some non-existing LDAP groups. My problem could be solved by running the UME consistencies check tool to repair the inconsistencies (described in SAP note 1016283).
Your issue might be differnt, but maybe it helps.
Best regards,
Benny