Jobs and tasks is running in Altiris server

I have created the software delivery to my users PC, and I try to push out this Jobs as fast as I can, and I use job and tasks, but just showing in queue, never run at all, later it will show failed.

I reboot my task server but still the same.

I RDP to some of machine found out the job has been delivery to those PC, I evern RDP to some of machines, it show client configuration has been done.

what should I do?

Thanks

Lillian