I can confirm this bug on Ubuntu 10.04 with Gwibber 2.29.90-0ubuntu1.
2010-02-18 18:07:01,911 - Introspect error on com.Gwibber.Accounts:/com/gwibber/Accounts: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.ServiceUnknown: The name com.Gwibber.Accounts was not provided by any .service files
2010-02-18 18:07:01,912 - Introspect error on com.Gwibber.Streams:/com/gwibber/Streams: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.ServiceUnknown: The name com.Gwibber.Streams was not provided by any .service files
I can confirm this bug on Ubuntu 10.04 with Gwibber 2.29.90-0ubuntu1.
2010-02-18 18:07:01,911 - Introspect error on com.Gwibber. Accounts: /com/gwibber/ Accounts: dbus.exceptions .DBusException: org.freedesktop .DBus.Error. ServiceUnknown: The name com.Gwibber. Accounts was not provided by any .service files Streams: /com/gwibber/ Streams: dbus.exceptions .DBusException: org.freedesktop .DBus.Error. ServiceUnknown: The name com.Gwibber.Streams was not provided by any .service files
2010-02-18 18:07:01,912 - Introspect error on com.Gwibber.
Twitter seems to be the only not to work.