Linkbutton unintentionally opens new window

[DMS]

I have a linkbutton on a form which calls a method in my codebehind.

It usually works fine, but every once in a while, clicking the link
will cause a new browser window to open. I think it happens when the
user quickly presses the link before the screen is done reloading.

Has anyone else seen this? Is this normal behaviour? What is causing
it, and what can be done about it?

Thanks in advance,
-Don