4.2 IP Multicast issues

Hi,
I was working with Spread 4.1 using multicast addresses with no problems and when I switch to 4.2 it doesn't work anymore.
I get an alarm and exit with the following error:

[Wed 09 May 2012 16:13:35] DL_init_channel: problem in setsockopt to multicast address 239.10.10.10 
Exit caused by Alarm(EXIT)

I check the code in data_link.c and I do not see much differences with the previous version.

My configuration looks like this:

Spread_Segment 239.10.10.10:4803 {
 	ASD-SC1	10.21.69.51 
 	{
 		D 10.21.69.51 
 		C 127.0.0.1
 	}
 	ASD-SC2	10.21.69.52 
 	{
 		D 10.21.69.52 
 		C 127.0.0.1
 	}
 	ASD-SC3	10.21.69.53 
 	{
 		D 10.21.69.53 
 		C 127.0.0.1
 	}
 	ASD-SC4	10.21.69.54 
 	{
 		D 10.21.69.54 
 		C 127.0.0.1
 	}
}

This config file works with 4.1.

Have there been any changes on this area?

Thanks, 
Marcelo