Calendar: scrolling makes events dissapear?

See 1.png , 2.png , 3.png. One event disappears if I scroll the calendar one step. Then it appears again after scrolling another step.

I have observed similar behaviors with other events. What may be happening here?

Using Smartgwt 4.1p power 17.01

Attached Images

	1.png (14.2 KB)
	2.png (9.9 KB)
	3.png (9.3 KB)