If your ImageCue worked properly with a single display, but now you've added an HDMI Splitter and don't have a picture, here's what you need to know:

Many of the inexpensive HDMI Splitters on the market cannot handle frame refresh rates other than 50Hz or 60Hz.  In 1920x1080 resolution modes ImageCue outputs at 24Hz or 30Hz.  The splitter must be capable of handling these refresh rates.

A splitter that we have found to work with ImageCue at 1920x1080p 24Hz and 30Hz is the Bytecc Model HMSP102K which is available from several online sources.  They also make a 4-way splitter.