I solved the problem, but am not sure why.... I switched the switch with a wireless router ( that sort of acts like a switch with one cat5 in and 2 cat5 & 1 cat6 out) that was downstream and everything now is ok. Thw wireless router has generates a poor wireless connection in this location, but we have everything hardwired now anyway. Thanks
Cat6 is compatible with Cat5 cable. It's just a higher grade cable that allows for higher transmission rates over the line. That said, there is no Ethernet protocol that can use anything beyond Cat5e (GigE), so using Cat6 outside of an environment where there is electrical noise is a waste of money.
Your problem was probably with a bad cable or you needed a crossover.