Strange horizontal lines

I am using dhtmlxGrid and I have two grids on a single page. One of the grids I am toggling style=“display:none” and style=“display:block” to hide and show the grid. The issue I am having is when I hide the second grid the other grid displays strange horizontal row lines randomly down the rows. Is there a refresh function I can use to refresh the view of the grid besides setSizes() or is this a known issue with another fix? Any help would be greatly appreciated.

strange horizontal row lines randomly down the rows
There is issues in rendering engine of FF which can produce similar effects, all default skins configured to workaround problem.
Do you use some custom skin|css ?

In common case you can force browser to redraw area by using next code snippet

    grid.obj.border=1;
    grid.obj.border=0;

If problem still occurs for you - please provide more detail ( screenshoot of problem or any kind of sample where it can be reconstructed )