The Slow Motion button (and / or macros) do not work well.
Unfortunately, the DirecTV H2x and especially the HR2x models are known for getting laggy and slow to respond over time. Macro reliability depends on a healthy home network and more heavily on the responsiveness of the DirecTV receiver. The pro version allows you to adjust macro delays. While the default settings should work well for most network environments, you can try increasing the delays if you continue to have problems. Try increasing them in 250 ms increments. If you find that your receiver has been sluggish or macros don't work as well lately, try rebooting the receiver. It should also be mentioned that immediately following a reboot, the receiver can sometimes be slow the first time or two when entering the guide, menus or viewing the Info banner. For this reason, you may want to manually navigate these after a reboot before attempting to use macros. For a bit more related information on this problem, see this question.
Tags: Macros, Slow Motion