Cisco Catalyst 2950 and Intertel IPRC cards

We made a change from Netgear switches to Cisco 2950’s to upgrade our network, and now we are having intermittent problems with our Intertel IP phones cutting out. We are also having problems with our RFID readers timing out while reading tags. How should we have these switches configured? Didn’t have this problem on the Netgears. Any help would be appreciated.