Sure! I have a data driven pages .mxd with a drainage network added to the view. I have enabled the flow direction arrows on the network with the utility network toolbar. The arrows appear on the map views in the mxd but when exporting to pdf do no show up (jpeg works, etc). I've done some testing and with the same data/same everything else, but data driven pages not enabled (ie one of my 29 maps at a time...), this does not occur.
(the scale/legend/etc was removed by me and looks fine upon export)