Redhat clsuter reboot due to Heuristic timeout

[vahab]

Hi,
I have installed a two node redhat cluster on RHEL 5.8
I have defined a quorum as below :

<quorumd interval="2" label="mycluster" min_score="2" tko="5" votes="1">
<heuristic interval="2" program="/usr/share/cluster/check_eth_link.sh bond0" score="3"/>
</quorumd>

And here is check_eth_link.sh :

#!/bin/sh
ethtool $1 | grep -q "Link detected.*yes"
exit $?

From time to time one of the node got reboot and this is the entry in logs just before reboot :

Dec 18 17:32:27 node1 qdiskd[8730]: <info> Heuristic: '/usr/share/cluster/check_eth_link.sh bond0' DOWN - Exceeded timeout of 8 seconds
Dec 18 17:32:27 node1 qdiskd[8730]: <notice> Score insufficient for master operation (0/3; required=2); downgrading

But there is not any issue on my network. I would like to know
1. Is my configuration correct or it can be better ?
2. Is there any way to increase timeout to a value more than current which seems to be 8

Any note that may help me is highly appreciated.
Thanks,