Hello. am having a hard time enabling stacking for two s5720-ie switches. I have placed the stack modules with two ports each at the back of the switches. I've tried changing the priorities as well as the slot numbers for one of the switches but when I type 'display stack', I only see the id and mac-address of only one of the devices. I have tried different manuals but they have not been of much help. I guess its probably the model. please help. I need to know what am missing. Thanks in advance