Basically I've sent animations to contacts on my list and some of them have said "huh, why did you say <hmm>" because they didn't have MSN Messenger 7/Messenger Plus! and therefore couldn't see the animation. There should be a feature somewhere within Messenger Plus! that (maybe when you rollover a contact on the contact list) displays what version of MSN Messenger they're using (i.e. 6.2/7 etc.) and/or whether they have Plus! installed. It's the same with the sounds I believe. If someone doesn't have the modern versions of Plus! and they recieve a sound, they see gobble-do-gook code. The best thing would be is for Plus! to check if they have a sound-animation compatible version of Messenger/Plus! and displays a message saying you can't send sounds/animation because the contact's Messenger/Plus! version is outdated/old and doesn't support the feature.
I probably didn't make a whole loads of sense above
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