Here is my situation.
We have a Cisco throughout the facility, but the two locations where we are using the SG300-10P we have an issue with headsets attached to our Cisco 7945 phones.Attached to any other of our switches (mostly Catalyst 3560E series) there are zero issues with the same phone/headset combo.
We are using various model Plantronics headsets on our phones. When the phone is attached to the SG300-10P switch, using the headset causes severs static on both ends of the conversation. The static goes away if the microphone is muted.. There are no issues if the same phone is moved to one of our other POE switches (Catalyst 3560)
Has anyone seen this issue before? Is there a solution? There are 2 firmware versions for the SG300 and either of them does not affect this issue in any way.