This is a SWAG, but does your app use a data-driven framework? For example, Visual FoxExpress 5, by default, runs in a mode where form and control properties are looked up at runtime from a table, which is slow. There is a way to write the values to the controls permanently at compile time which speeds things up by a factor of 3 or so. If you modified your app and forgot to perform this step you might see this kind of effect, depending on how the framework works.