Graphics bug: drawCircle doesn't draw a circle when using large pen width

I am getting this both on the simulator and on my 935. SDK 2.3.5, Eclipse MARS.2. FW 8.1 on the 935. I have been made aware there are issues with the graphics API and this seems to be one of them. drawCircle produces a circle up to a pen width of about 8. Above that it starts going wonky.

Trying to draw a 'doughnut' produces a squared off circle with a squared off hole:

dc.setColor(Gfx.COLOR_DK_GREEN, Gfx.COLOR_TRANSPARENT);
dc.setPenWidth(20);
dc.drawCircle(120, 120,30);

This however produces a nice circle with a round hole:

dc.setColor(Gfx.COLOR_DK_GREEN, Gfx.COLOR_TRANSPARENT);
dc.setPenWidth(20);
dc.drawArc(120, 120,30,0,0,0 );


One the left is drawArc, on the right is drawCircle