I've just split a gigabit interface on my 7301 into two dot1q interfaces and set the other end point interface (Cat6513) as a trunk only allowing the two VLANs.
Before this setup I had no incoming errors on the 7301 but after about half a day I see the figures below on the 7301
170912969 packets input, 85343674837 bytes,
Received 3013 broadcasts, 0 runts, 0 giants
122247 input errors, 0 CRC, 0 frame, 122247 overrun
The overrun counter is constantly incremented. Both the physical interface on the 7301 and the one on the 6513 has VLAN 1 set as the native VLAN. Is that a problem? I could hardly see that a perfectly working interface should get hardware errors just because I alter the VLAN tagging.