Hi,
There are a few forum threads on this topic. Here's a link to a post I made earlier with an explanation of why this occurs and what can be done about it:http://forums.infragistics.com/forums/p/19171/70448.aspx#70448
Hi, What you can do is to configure te button as postbacktrigger, that option is able in updatepanel's properties in triggers, sorry by my english, hope can help you!!
Is not possible? :(