Sorry, I misread your question. Insert the following inside your custom module code. Replace 'ch33zylici0us' with your sn. Sorry the icon doesn't work.
CODE
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<b>AIM:</b> </span><span id="profIM11"><img border="0" align="absmiddle" src="http://big.oscar.aol.com/ch33zylici0us?on_url=http://www.aol.com:80/aim/gr/online.gif&off_url=http://www.aol.com:80/aim/gr/offline.gif"> <a href="aim:goim?screenname=ch33zylici0us">ch33zylici0us</a></span></span>
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If that still doesn't work, use the regular aim option in xanga for regular modules (make them show just temporarily). Then go to view source and take your aim code, and THEN place that into your custom module. Thats what I did.
I hope that helps.