Skype

We've downloaded Skype onto the computer with hopes that it will provide us with free phone calls to family and friends. However on the first try, it appears that we don't have a strong enough internet connection, which seems odd since we're at an internet cafe. The guinea pig was Kristen's sister, Angela, and she got 3 hang-ups and then 2 10 second phone "conversations" with Kristen, before the connection quit.
So, for all the skype users out there, is this our connection giving us difficulties, or is there some skype trick that we need to learn? I called the 800 number for UPS to test it and I was able to get a 30 second phone call.