>But, what about when open vfp, issue a DO FORM on the problem form, then issue CLOSE DATA ALL, and then try a MODI FORM on it? In other words, I only want to know if caching is affecting anything or not.

>
>This is important to my testing & diagnosis attempt.

In this case MODIFY FORM is slow.
Caching does not seem to affect this.
The data files MUST BE OPEN when you issue MODIFY FORM.