jit.lcd drawpict not working with matrix?

The documentation says:

drawpict    pict-name [symbol]
...
Draws the named picture or matrix.

However, I have no luck getting jit.lcd to display anything this way.
I read a frame of a movie or an image into a named char matrix, say test, then try to use drawpict test 20 20
to display it at hit.lcd location 20 20. But Nothing happens.
Something like this was reported fixed in Max 5.