FOW Leaves Slivers Showing Through....

I've been doing some testing in prep for my first use of Roll20 with my group.  Using FOW I revealed a large area of the map.  I then hide it again.  Where ever I hid the map there are small slivers of FOW that are still revealed.  Here is a screen capture.  Hmmm once I upload it here it must be resizing the image and the slivers are only like a pixel wide so I seem to be losing the example.  Looks like the Shards have gone down again so I cant test it anymore. :(

OK, figured it out.  On any Zoom level below 100% you see the slivers appear.  Just create a new page.  Turn on FOW.  Start hiding areas and even on the GM screen you will see the slivers, hard to see unless you change the GM's FOW colour to Black, but its there.  Both in Chrome and Firefox.  Every time you hide more FOW more slivers appear.  I can't show a screen capture since the slivers are like one pixels wide so they disappear on the file once I upload it here.