Does Yahoo Messenger Use Data When Signing In??

well i have a question about my yahoo messenger, i tried googling and what not, but didnt find a specific answer to what i was looking for.. nd its 12 midnight so sorry if my spelling and grammer is badd... but i was wondering if signing to your yahoo messenger uses up data, becuase i dnt have a data plan and everytime i sign up on yahoo on my fone the loading bar kinda scares me cuz i dnt know if its data or what... nd these red wave marks pop up on where the 3G logo is... so im wondering if sigining on YM uses data, i searchd ATT nd they usually sed that YM is like txt messaging...

i actually have a question that is dealing with this (and I did search) but this is confusing... when you go to
Menu>Messaging>IM>Yahoo!>More>Proflie Settings>
you get a choice of: medianet, at&tmms, and at&tims.
I have unlimited messaging which (as you prolly know) inclues IM. but why does it say MEdia Net? should it be one of the other choices or am I just confused?

you could always contact att and they "may" know or jsut try to confuse you. or if that does not work just log in to im for a few send a couple of IM and exit and later check to see if data was used

Agoat is right, you won't get charged for using Messenger if you have unlimited text, or even if you pay for only a few texts a month, every message you send through messenger counts as one text and the same for if you receive, I have talked to them personally on this because I wanted to make sure when we got unlimited text that I wouldn't get a surprise bill.