EtherChannel, Load Balancing and Forwarding issue

[mahmoud.hattab]

I have 2 Cisco 2950G-12-EI, I need to connect 3 redundant cross-cable from S1/P1-P4 to S2/P1-P4, each switch has host connected on it, HostA and HostB. I want to Ping HostA from HostB without a timeout. I succesfully done this with 2 redundant cable, using (config-if#channel-group 1 mode on) to all ports of S1 and S2 a total of 6 ports in one channel-group 1, but if I join another two ports on that group the S2 is shutting down all the LED light not included the port of the HostB. Please let me know if how I can load balance if I create a 2 channel-group, so that I can maximize each group of only 6 ports. Please help me about this issue, thanks. I attached here a copy scenario diagram.

[glen.grant]

If its shutting down something is not configured right . Create your channels this way , on the ports use the command "channel-group 1 mode desirable non-silent" this will let the switch negotiate the channels. All ports must be setup the same with speed and duplex. You should be able to bundle up to 8 ports together.