nvidia driver 358.09 stereo displays do not work

When using 358.09 on two different boxes running recent (15.04) versions of ubuntu, my screens that are setup for stereo display (on a K4200) fail to work. reverting to 355.11 fixes the problem on at least one box (and presumably the other one – about to try).

Can you please generate and attach an nvidia-bug-report.log.gz file?