Yahoo!Groups is being affected by a network connectivity issue that is
affecting a number of Yahoo! properties. This issue is not specific to
Groups. We are working with the Yahoo! Network Operations team to
resolve the problem, which began Friday April 27, at approximately
8:00 a.m. Pacific (http://www.timeanddate.com/worldclock/).

We do not have an estimate of when this will be resolved. We will keep
you updated via the Groups team blog:
http://blog.360.yahoo.com/y_groups_team