Conversation window: Chinese/Japanese/Korean IME (Input Method Editor) reset to English in the Messenger conversation window
On a computer running Windows XP SP2 or SP3, if you receive an instant message while the Messenger main window is closed, and then try to type Chinese, Japanese, or Korean characters in the conversation window using IME, the input mode will be reset to English and you won't be able to input Chinese, Japanese, or Korean characters. To resolve this, reopen the Messenger main window and then resume typing in the conversation window.
Video: Webcam control and effects add-ins may stop working and not appear for webcams
Some webcam manufacturers provide controls for camera operations or effects that you can apply to the video experience within Messenger. These add-ins may stop working. If you don't see the webcam manufacturer's camera control and effects icon under your display picture in Messenger during a video call or webcam session, please consult your hardware manufacturer for an update.
Voice and video calls to Messenger beta or Messenger won't work
Voice and video calls can't be made between the beta version and the new release version of Messenger; or between Windows Messenger and release version of Windows Live Messenger. To use voice and video calls, the sender and receiver both need to install the latest version of Windows Live Messenger from http://download.live.com.
Sharing photos: Supported file types for sharing photos in Messenger
Messenger supports only .png, .jpg, .bmp, and .gif image formats. Any other image formats may not work correctly in Messenger.
Sharing photos: Photos can't be saved after a contact stops sharing photos
You can save photos in Messenger only while both people are actively sharing photos. If your contact has stopped sharing photos, you won't be able to continue saving photos.
Groups: Group members might not be able to join the group conversation
Sometimes group members appear online or available under a group within the Messenger main window, but are unable to join the group conversation. This happens when a group member is using a program that doesn't support groups, such as a previous version of Messenger, Xbox, Messenger for mobile, etc.
Groups: The group status shown in the Messenger main window may appear to conflict with the status of members within the group
It's possible that the status for a group may appear as offline, while members of the group listed below the group name in the main window may show as online. This is because the group status message shows the behavior when the group conversation window is opened.
Groups: The group's e‑mail address doesn't appear in Messenger
There's no entry point to the group's e‑mail address in Messenger. If you want to see the group e‑mail address, right-click the group's name in Messenger, and then click Go to group website. On the group website, you can see the group e‑mail address.
Groups: Some actions can be done only on the group's website
Some management actions (such as viewing or canceling pending invitations, removing members, and changing member roles or a group's name) can be done only on the group's website. To do these tasks, you must be an owner of the group. To quickly access the group management pages on the web, right-click the group in the Messenger main window, and then click Group Settings.
Groups: When inviting new members, you can't see who has already been invited
When you're selecting contacts to invite to a group, Messenger doesn't filter out any contacts who have already been invited to the group. However, contacts who have already been invited won't receive a new invitation.
Users under 13 with limited privileges can't sign in to Messenger
In accordance with permissions on the account, users who are younger than 13 years old (according to their Windows Live ID registered information) whose account privileges have been set to Limited won't be able to sign in to Messenger.