Same things happens to me. Today I upgraded two things sendmail and syslogd (what a coincidence! :). After few minutes I found that `ps ax' shows a lot of sendmail processes. Everything looks like that after restarting *syslogd* information goes into appropriate files for few minutes. Then it stops, what results in sendmail (and, I believe, other processes that make us of syslog) to wait forever.
When I downgraded sysklogd back to -26, everything runs fine. -- Mike