3560 with 7940 and PC hanging off 7940. PC is experiencing some pretty bad slowness often. Should I hardcode the speed and duplex on the 3560 port?? Would it mess up the phone?
verify what is doing the phone when the PC has slow connectivity we have seen that if the phone registers/deregisters often the downstream PC can suffer of this.
I wouldn't hardcode the speed and duplex because there is no way to configure the phone.
Look also at the 3560 logs to see if there are messages about POE events related to the port where the phone connects to.
Also we had few cases of phones with a no working PC port.
If you have a chance connect the same PC to the PC port of another phone in the same room and see if the behaviour changes.
Hope to help