When the combbox is clicked on a task bar button appears. Only top-level windows should have a task bar button.
Fixed in Oct 6, 1999 3:02PM build.
This can be tested by clicking on any combo box and observing that it no longer creates a blank button on the task bar.
Don't see anything changing in the Taskbar using the 1999111016 M11 build under NT. Marking verified fixed.