SW Test Automation Framework

It actually start running..after I terminate one of the job that I ran.
What actually happen?

before I terminate one of the job, The one that can't run have this in stax job log

20090617-00:30:06 Start JobID: 49, File: C:/Documents and Settings/Administrator.ADS/Desktop/TESTSYSTEMXML/SmokeTest.xml, Machine: local://local, Function: main, Args: {'GProc3264': '32', 'GSTAXMachine': 'xxx', 'GMachList': ['xx'], 'GAddress': ['xx', 'xx', 'xx'], 'GDLLDebugRelease': 'debug', 'GTestNumber': [7000], 'GTestVer': 'smoke', 'GServer': 'xx'}, JobName: <N/A>

but after I kill one of the job the one that can't run before start running and have this in stax job log


20090617-00:30:06 Start JobID: 49, File: C:/Documents and Settings/Administrator.ADS/Desktop/TESTSYSTEMXML/SmokeTest.xml, Machine: local://local, Function: main, Args: {'GProc3264': '32', 'GSTAXMachine': 'xxx', 'GMachList': ['xx'], 'GAddress': ['xx', 'xx', 'xx'], 'GDLLDebugRelease': 'debug', 'GTestNumber': [7000], 'GTestVer': 'smoke', 'GServer': 'xx'}, JobName: <N/A>
20090617-10:11:24 Info Received HOLD BLOCK main request
20090617-10:11:24 Info Holding block: main
20090617-10:11:24 Info Received RELEASE BLOCK main request
20090617-10:11:24 Info Releasing block: main
20090617-10:11:45 Info Received HOLD BLOCK main request
20090617-10:11:45 Info Holding block: main
20090617-10:11:45 Info Received RELEASE BLOCK main request
20090617-10:11:45 Info Releasing block: main
20090617-10:12:05 Info Received HOLD BLOCK main request
20090617-10:12:05 Info Holding block: main
20090617-10:12:06 Info Received RELEASE BLOCK main request
20090617-10:12:06 Info Releasing block: main

So, what actually happened here? what does received hold block main request means.

thanks.