Here is another link I found that describes this anomalous situation:

http://aspalliance.com/articleViewer.aspx?aId=829&pId=-1



>Well, we can invent some slightly complex solution. In button's Click event we would set some hidden field value to 1
>
>In onClientClick event we would check if it's 1 set it back to 0 and return false preventing the second immediate click. We would have to either write this as a JavaScript function or even inject the script.
>
>Sounds quite convoluted solution, may be you should better ask this question also in ASP.NET forums.
>
>>I stand corrected... further testing reveals what I had thought would happen. Not disabling the button still allows for it to be clicked again and posts the record multiple times. This is a catch-22 situation.
>>