Description of problem:
If multiple event sources are configured on an agent, not all of them are polled. It is not clear what actually causes this issue but it happens every time. 

Version-Release number of selected component (if applicable):
4.4.0.JON312GA
4.7.0.JON [adad71f]

How reproducible:
Always

Steps to Reproduce:
1.  Start JBoss ON 3.2 system.
2.  Import RHQ Agent and RHQ Server into inventory.
3.  Create /tmp/generateLog using the script below.
4.  Then run /tmp/generateLog to generate our random log data
        
        chmod +x /tmp/generateLog
        for i in $(seq -w 0 10); do /tmp/generateLog /tmp/file-${i}.log 2>/dev/null & done

5.  Modify RHQ Agent resource configuration Event Report Max Per Source and Event Report Max Total to 1000 and 10000.
6.  Add 11 event logging sources to RHQ Server resource using generated log files /tmp/file-00.log, /tmp/file-01.log, /tmp/file-02.log, ..., /tmp/file-10.log
7.  Restart agent with DEBUG logging enabled.

File: /tmp/generateLog
------------------------------------------------------------------------
#!/bin/sh
#

maxSleepTimePerSleep=2
maxEntriesPerSleep=5
maxEntries=1000000
maxSleepTime=3600





logLevels=("FATAL"
"ERROR"
"WARN "
"INFO "
"DEBUG"
"TRACE")

logThreads=(main
$(echo Thread-{0..99})
$(echo Fake-{0..9}))

logCategories=(apache.cassandra.db.commitlog.CommitLogReplayer
org.jboss.as.server.deployment 
org.jboss.as.messaging 
org.some.other.category)

logMessages=("A log message"
"Another log message"
"A log message with some meaning"
"A log message without any meaning"
"To be a log message or not to be"
"To infinity and beyond"
"Every rose has its throne"
"Come out and pay"
"That thing wasn't supposed to do that."
"Now that's what I'm talking about"'!'
"Friends don't let friends eat grapefruit")

function printRandomLogLevel() {
    numLogLevels=${#logLevels[*]}
    echo -n ${logLevels[$((RANDOM%numLogLevels))]}
}

function printRandomLogThread() {
    numLogThreads=${#logThreads[*]}
    echo -n ${logThreads[$((RANDOM%numLogThreads))]}
}

function printRandomLogCategory() {
    numLogCategories=${#logCategories[*]}
    echo -n ${logCategories[$((RANDOM%numLogCategories))]}
}

function printRandomLogMessage() {
    numLogMessages=${#logMessages[*]}
    echo -n ${logMessages[$((RANDOM%numLogMessages))]}
}


function printLogTimestamp() {
    timestamp=$(date +"%F %T|%N")
    ms="$(printf "%03d" $(( 10#${timestamp#*|}/1000000 )))"
    echo -n "${timestamp%|*},${ms}"
}

function printRandomLogEntry() {
    echo "$(printLogTimestamp) $(printRandomLogLevel) [$(printRandomLogThread)] ($(printRandomLogCategory)) $(printRandomLogMessage)"
}

function printRandomLogEntries() {
    totalSleepTime=0
    totalEntries=0

    while [ true ]; do
        randomSleep=$((RANDOM%${maxSleepTimePerSleep}))
        [ $((${maxSleepTime}-(${totalSleepTime}+${randomSleep}))) -lt 0 ] && randomSleep=$((${randomSleep} +(${maxSleepTime}-(${totalSleepTime}+${randomSleep}))))
        echo >&2 Sleeping for ${randomSleep} seconds...
        sleep ${randomSleep}s
        totalSleepTime=$((totalSleepTime+$randomSleep))
        randomNumEntries=$((RANDOM%${maxEntriesPerSleep}))
        [ $((${maxEntries}-(${totalEntries}+${randomNumEntries}))) -lt 0 ] && randomNumEntries=$((${randomNumEntries} +(${maxEntries}-(${totalEntries}+${randomNumEntries}))))
        echo >&2 Printing ${randomNumEntries} log entries...
        for ((i=0; i<randomNumEntries; i++)); do
            [ $# -gt 0 ] && {
                echo $(printRandomLogEntry) >>"$1"
            } || {
                echo $(printRandomLogEntry)
            }
        done
        totalEntries=$((totalEntries+${randomNumEntries}))
        [ ${totalEntries} -ge ${maxEntries} -o ${totalSleepTime} -ge ${maxSleepTime} ] && break
    done
    echo >&2 Total entries is ${totalEntries} and total sleep time was ${totalSleepTime} seconds.
}

printRandomLogEntries $@
------------------------------------------------------------------------

Actual results:
Agent log (after restart and debug is enabled) will only contain log messages for a single log file source instead of all 11:

2013-09-18 14:54:59,669 DEBUG [EventManager.poller-1] (core.pluginapi.event.log.LogFileEventPoller)- /tmp/file-10.log: 24405 new bytes
2013-09-18 14:55:59,668 DEBUG [EventManager.poller-3] (core.pluginapi.event.log.LogFileEventPoller)- /tmp/file-10.log: 20126 new bytes
2013-09-18 14:56:59,668 DEBUG [EventManager.poller-1] (core.pluginapi.event.log.LogFileEventPoller)- /tmp/file-10.log: 23275 new bytes
2013-09-18 14:57:59,669 DEBUG [EventManager.poller-1] (core.pluginapi.event.log.LogFileEventPoller)- /tmp/file-10.log: 25691 new bytes


Expected results:
Agent log (after restart and debug is enabled) will contain log messages indicated events are being collected from all 11 files.

Additional Information:
If I disable an event source in the JON UI and then re-enable it, events will be collected for that source. This is true for all the sources. But, as soon as the agent is restarted this problem comes back.