Here's the response I got from DigiChat:
We have received many such complaints over the past week or so. This
problem is related to the slow connection times between many of our users
and the chat hosting machines. The problem lies somewhere within Alter.net
and not with our host or the machines themselves. We have informed all
involved parties, and are working closely with our host provider, DellHost,
to isolate and resolve the problem. We hope to reach a quick and complete
resolution. Thank you for your patience. If you have any more questions
please let us know.