Losing packets between switches

Hi, I have a 6248 and a N1548P they are linked through an UTP cable, the problem is that I'm having constantly packet loss when I ping from the 6248 to the N1548P.

I've already tested the cable and it is not the cause.

As the N1548P is a POE switch, is there any problem with connecting it to the 6248 which is not POE ?

Also, on RMON Statistics I've seen oversize packets on the port used for the uplink what is that means?

Any help will be appreciated.

Thanks