EchoLink Problem

Hello,
Echolink program is installed fine. My computer McAfee security is programmed to pass correct ports. Windows firewall is off. My Linksys router is programmed to pass correct ports. I receive the listing of stations. The problem is I am unable to communicate with anyone MOST OF THE TIME! This is the strange part. Every few days it works fine. Then, when I close the program it's gone again until many days later it begins to work. This is on the second computer. On the lead computer Echolink works all the time. My question then is, if it works now why not 5 minutes from now? Any suggestions? Thanks. 73