I have a 2 C3750G-12S's in a stack running c3750-ipservicesk9-mz.122-44.SE. On one of the 3750's some (not all) of my interfaces are showing an excessive number of symbol frame errors and the interfaces are bouncing up and down from time to time. On the other switch in the stack this does not happen. I have tried swapping out all hardware, patch cables, etc with the same result and had the fiber tested as well. The only thing I can find is that the problem is specific to this switch. I opened a case with Cisco a couple months ago about this and they sent a replacement switch, however the problem still seems to be occuring.. Any ideas on what else could be causing this?
I have this problem too.