fast ethernet limits

Hi NANOG, Could someone please help me with a fast ethernet problem I am having. We have a POP in a 27 floor building, and have a rj45 run from the the bottom of the building (in the telco room) to the top of the building. We have cisco switches on either end and we are seeing about 5-20% packet loss on the trunk. Are we running into a distance limitation of fast ethernet, or are we suffering from another problem? I read that 328 feet is the limitation of fast ethernet. Is there anything short of getting a repeater for the cable run that I can do to boost the signal? TIA for your help. Ciao. Steve Rude