I've been fighting with a grid for quite a while now and I remember once again why I rarely use grids.

I have a container with a bunch of controls dropped into a single columncount grid.

The container uses the pk of the grid recordsource to retrieve data for display. Originally I was trying to allow the user to implicitly edit directly in the grid but that turned out to be full of little quirks that I couldn't work around. The grid would work 90% of the time and fail 10% with no rhyme or reason. So now I switched the grid interface to an explicit edit whereby the user has to click an edit button in the row to enter edit mode. For various reasons using the container in the grid proved problematic and full of quirks that I couldn't work around. I thought I could emulate a direct in the grid edit by hosting the grid row container in a naked form and placing it directly over the edited row via a modal call. This works really well and it looks to the user like they are editing the grid. Additionally, because of the modal form the user has to finish the edit (save/cancel) before they can do anything else in the form. This modal interface wasn't obvious so I used Bernard Bout's lightbox control to grey out the rest of the form. Now it's obvious to the user they have to finish their edit before they can proceed with any other changes.

Here's the problem and it's irrelevant to the lightbox:
Sometimes when I call the modal form everything on the original form halts and yields to the modal form.
Sometimes when I call the modal form the first form with the grid, now under the displayed modal form, stays busy doing something which I can't trap. The mouse icon stays hourglass and the response is sluggish on the modal form. Additionally, with the lightbox turned on, the busy form visible beneath the modal form flashes.

Any thoughts on what's going on? Why the form just pounds away on UI stuff?

In the second screen shot the form is busy flashing beneath the lightbox effect.