I was having flickering problems with some neo-neon LED fixtures. Several controllers (Dove, Whole Hog, American DJ) would work, but several (ENTTEC, Milford Instrument, Martin, ETC) would not. The problem came down to frame timing. The first units worked because they had 50-60uS frames, while the latter roared along at 44us which was too fast for the fixtures, so channels ran together.

Two fixes came of this, the first was to use a Dove Systems MPX-100. This is a hand held DMX generator, but also has the feature that it will take its DMX input and reconstitute it into a new stream(and at $295 is fairly cheap). Because of the interrupt timing Dove uses they just add an additional 6uS of mark time on the end of each frame to fit a 50uS clock. (I nearly cried to finally get out of DMX hell) --I then emailed ENTTEC who, within a day, made new firmware to pad their frame to 50uS. This will still work with 40 per second refresh and has worked perfectly. Special thanks to Harold at Dove Systems for his insight that pointed me in the right direction in my testing.