Hi, you can try to download the non beta version and its working fine !
You can also check this:http://www.helpbytes...blems.php#crash
it says there
'Ypager crashes or performs an illegal operation on startup or right click
This error occurs because you are using a third party skinning application that modifies the Windows Look/Interface.
You need to either remove the program, or open the settings, and disable the skinning of Yahoo! Messenger / YPager.
Two known programs to cause this are Window Blinds and AlienGUIse. Window Blinds has a "per application" setting to override this.'