Coldfusion 9 scheduled task is not running and mail connection failed

In my CF9, scheduled task able to running as normal and mail connection is connected but after sometimes (estimate 2 hours) these scheduled task stopped working and mail connection is failed.

All I need to do is reboot the server and everything back to normal but after 2-3 hours, it back to old sickness.

Here extra info from log:

1. Error while executing task unable to create new native thread

2. unable to create new native thread

I am running Coldfusion 9 on Win2K3 server with SSL.

Please help.

Thanks in advance,

Eric