Why does a chat box open on hotmail when im talking to someone on msn?

[Lovely Anderson <3]

this happens when im on hotmail, checking through my mail.
when i'm talking to someone on msn chat convo while on hotmail,
a chat box pops up at the bottom of the page and it says exactly what the person wrote, and if i close the chat box on hotmail, than the msn convo will close as well.
this probably involves my hotmail page "making it better" "adding new improvements", meanwhile it's causing me problems.

Does anybody know what i'm talking about?
because i only use hotmail to check my mail and nothing else.
Tell me what to do, do fix this, and the way i want it to be
step by step would be appreciated.