Strange issue. I have a new ESW-540-24P-K9 programmed with the same VLAN's as a 2950. When I connect the ESW to the 2950 via a combo port using a CAT5 cable it will pass VLAN information between the 2 switches and everything works fine. When I use the same combo port but connect via an SFP to the 2950's GBIC it will not pass VLAN data. All ports being used are set up as trunking ports and I have tried several configurations on both the 2950 and ESW. no matter what I try the ports on the ESW will only pass VLAN traffic if using copper...not the SFP. Only difference between the 2 set ups is that the combo port on the ESW connects to another copper port on the 2950 not the GBIC port when it works, but the GBIC port and coper port on the 2950 are programmed exactly the same. Any thoughts?