A focus switch between an edit control and a button control occurs very slowly on a computer that is running Windows Server 2008 or Windows Vista
Consider the following scenario. On a computer that is running Windows Server 2008 or Windows Vista, you use a non-English Input Method Editor (IME) in an application that contains edit controls and button controls. For example, you use the Japanese IME. An edit control uses the IME for input context. In this scenario, when you switch the focus between the edit control and a button control, the focus switch occurs very slowly.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB950528.