I have owned a 788 CI and 898 SI with the Interlink for a couple of years now with no issues... Love IT!

I bought a brand new G3 back in November and it had a 788 CI HD on it. I installed my current set-up on my new boat and went fishing the next day.
I then put the 788 HD model on the front base and linked it up.... Big mistake as it had corrupted data in it and it totally screwed up my 898 and itself. Like a dummy I thought well lets try to erase all the data on the interlink and the 898 and plug in the old 788 CI and link it up.... Bad idea as it not only had the 898 messed up but now both 788's.

I contacted Humminbird and I sent them all three units and the interlink and they fixed everything FREE of charge.
They had to replaced parts on the circuit boards on both older units.
Now everything is like brand new again.

Thanks Humminbird!