How not to do UI Design in Just Three Widgets

Here we have an application that lets you schedule various tasks to happen at regular intervals (exactly what tasks doesn't matter for this discussion). The screenshot on the right is the dialog that lets you set the time interval between invocations of the task. Seems pretty simple at first glance. The default interval is four seconds. The first piece of confusion comes from looking at the spinner control. Does it change the number field or the units field? Clicking on it doesn't answer the question - nothing happens when you do.
Hmmmmm. Maybe we can come back to that spinner. Let's try and edit the number of seconds in the interval from 4 to 6. Ok. Clicking in the number field gives us a cursor - it's obviously an edit control. Unfortunately, it appears that the field can't be changed by typing numbers on the keyboard. Maybe if I.... Ah, yes. Now that the field has the keyboard focus, clicking on the spinner changes the number. It only changes it by one each click, though. I guess to change the interval to 130 seconds I'm just going to have to click on that up-arrow 126 times. (...and no, holding down the mouse button on the spinner doesn't work)
Now I want to change the units from seconds to something else. Guess what? It's another one of those almost-editable text fields. I'm starting to grok the mind-space of the programmer of this dialog by now, so it isn't long before I try that spinner again...
...and, sure enough, it works, changing the units from seconds to hours. This sort of widget re-use is probably saving me big in System Resources. I bet the app runs smooth as teflon-coated snot on Windows 3.1 I don't want hours, though. I want minutes. So I press my trusty mouse button one more time. Nothing happens. Why? Well, notice how the units text field resized itself to fit new word "hours" (which is shorter than the previous "seconds"). This caused the spinner to move to the left, too (so much neater that way). In fact, it moved itself right out from under my mouse pointer. So to pick a new interval unit not only do I have to click multiple times until the one I want comes up, I also have to chase the spinner widget around the screen after each click. One last thing. Normally I'd take the "Apply" button on a dialog to mean "Apply the changes but keep the dialog open". The "Apply" button here closes the dialog.