Ok, I think I solved this. When Multisim runs a simulations it collects data up to a fix number of points. If the number of points is to small, with the used used time resolution, to allow for a full trace to be captured, it will be "clipped" on the Multisim oscilloscope. I don't have the correct terminology for this, but if anyone finds it useful I attache a screen shoot below. Note the arrow, when number of points is increases to 928000 a full traces can be captured.
**broken link removed**