I was having countless issues with getting video into my IO LA, I had reset my prefs/ deleted them, restarted, checked cables etc. I called AJA at 1-530-271-3190, limited hours, but they will give you LOTS of help for free and very friendly tech support.
They told me to use the Easy Setups(always) when changing between decks/sources. So after all those problems I went to the Easy Setup for -8-Bit Betacam to NTSC DV- and it started working right away. The issue was, I had been resetting everything in the Audio/Video Setup, except the playback. For some reason with the IO LA- the playback has to be the same as the output, using the Easy Setup changed everything and matched the Video and Audio Playback to the input.
If you have issues during "normal" business hours be sure to call AJA at 1-530-271-3190