We have several switches that are connected to our Nexus 7k. Most switches that are trunked and are getting CRC errors on the access switch uplink ports. All switches that are connected via an access ports, have no crc errors. A WS-C3560G-24TS running 12.2(25)SEE2, trunked shows no errors, but all other similiar switches running a different IOS show CRC errors on their uplink ports. All 2960S-24TS running both 12.2(58)SE and 15.2(1) have errors. Our WS-C3750E-48TD running 12.2(37)se1 has no errors, but the other one running a different IOS do have errors. Any ideas why this is happening?