Very small blank window appears on Spark start-up

I have a dual-monitor setup, with my larger, secondary monitor positioned to the left of my primary monitor. Whenever I start Spark a very small blank window belonging to Spark appears above and to the left of my primary monitor. I’ve attached a screen shot to demonstrate the problem.

Any idea what this is and why it shows up? Sticking things “off screen” is often a shortcut to keep UI elements that create unnecessary windows out of the user’s way but that only works if you know that a given position will always be off-screen, an assumption that is easy to break with a multi-monitor setup. I’m guessing this small window is something like that. Am I right?

Closing the window has no apparent effect on Spark. Can anything be done to make it just not show up in the first place?

Which version of Spark do you use?

2.5.8, it says.