Evolution is now hanging in PR_Poll when trying to connect to an SMTP server:

Thread 5 (Thread 1181088688 (LWP 6390)):
#0  0x41569668 in *__GI___poll (fds=0x415cfff4, nfds=2, timeout=190674) at poll.c:86
#1  0x4054b2fb in PR_Poll () from /usr/lib/libnspr4.so
#2  0x452e6d43 in stream_connect (stream=0x9494f48, host=0xfd66fe0) at camel-tcp-stream-ssl.c:1133
#3  0x452e7018 in camel_tcp_stream_connect (stream=0x9494f48, host=0xba36) at camel-tcp-stream.c:107
#4  0x4580323b in connect_to_server (service=0xfd2b4d0, ai=<value optimized out>, ssl_mode=2, ex=0x4665f3fc) at camel-smtp-transport.c:263
#5  0x458038e6 in connect_to_server_wrapper (service=0xfd2b4d0, ex=0x4665f3fc) at camel-smtp-transport.c:437
#6  0x45804439 in smtp_connect (service=0xfd2b4d0, ex=0x4665f3fc) at camel-smtp-transport.c:475
#7  0x452dc6c3 in camel_service_connect (service=0xfd2b4d0, ex=0xba36) at camel-service.c:369
---Type <return> to continue, or q <return> to quit---
#8  0x452dd482 in camel_session_get_service_connected (session=0xfffffffc, url_string=0xfffffffc <Address 0xfffffffc out of bounds>, type=4294967292, ex=0x4665f3fc) at camel-session.c:261
#9  0x455b56fc in mail_fetch_mail () from /opt/gnome/lib/evolution/2.4/components/libevolution-mail.so
#10 0x455b3993 in mail_enable_stop () from /opt/gnome/lib/evolution/2.4/components/libevolution-mail.so
#11 0x40471458 in thread_dispatch (din=0x0) at e-msgport.c:826
#12 0x40b3f107 in start_thread (arg=0x4665fbb0) at pthread_create.c:261
#13 0x4157327e in clone () from /lib/libc.so.6
#14 0x4665fbb0 in ?? ()

This happened once before and mysteriously went away.  A reboot and removal of the *.db files from .evolution failed to improve the situation.