maximum port channel per VLT domain

Hi all,

I am new to Dell and i am ttying to set up in GNS3 a lab where i have an VLT domainand i try to create 2 vlt port channels between the 2 vlt-peers and 2 different cisco switches. SW1 and sw2 are DEll and Server and Core are iou_l2

 I create the first po and all is good. Problem is that when i create the second port channel (eg between vlt and core) the first one goes down. Is is a GNS bug or vlt domain can't support 2 vlt-port channels between different and-devices?

Thanks in advance