LinuxQuestions.org - Pinging problem - extremely slow response time

I have a Linux server (Redhat 6.2) set up in my local network of mostly Windows O/S. The problem I am having is the extremely slow response time when I tried to ping any other machine on the network. There's no problem pinging my linux server from all other machines. Just the other way round.

The response time I get keeps doubling it seems. The second response time is 74000 ms, and then 148000 ms and so forth.

When I use ping -n then the response time is normal.

I have spent days trying to resolve this with success. Tried all the suggestions posted in this forum for other problems. I must have missed something.

Thanks in advance.

ifconfig shows:

eth0 Link encap:Ethernet HWaddr 00:B0:D0:E3:4A:C5
inet addr:192.168.18.3 Bcast:192.168.18.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:44945 errors:0 dropped:0 overruns:1 frame:0
TX packets:34535 errors:0 dropped:0 overruns:0 carrier:6
collisions:89

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:3924 Metric:1
RX packets:108 errors:0 dropped:0 overruns:0 frame:0
TX packets:108 errors:0 dropped:0 overruns:0 carrier:0
collisions:0

netstat -r shows:

Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
mylinux01.abc.com * 255.255.255.255 UH 0 0 0 eth0
localnet * 255.255.255.0 U 0 0 0 eth0
loopnet * 255.0.0.0 U 0 0 0 lo

/etc/hosts shows:

127.0.0.1 localhost.localdomain localhost
192.168.18.3 mylinux01.abc.com mylinux01

/proc/sys/net/ipv4/ip_forward set to 1.

Route -n shows:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.18.3 0.0.0.0 255.255.255.255 UH 0 0 0 eth0
192.168.18.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 192.168.18.1 0.0.0.0 UG 0 0 0 eth0