all the patch does is change your registry seeting, u can do it manual without using like y-multi.

go to start> run> type in regedit in field box> click ok> it will open your registry…now look for this key..HKEY_CURRENT_USER>software>yahoo>pager>test>right click on test>make a new dword>name it PLural>right click on Plural>click modify>now change the value data from 0 to 1> click ok..than exit out registry editor

and you should be able to run multiple yahoo messengers at the same time
good luck & hope this info helped you