M-Audio Fast Track Ultra fisical input 1 appears in VST input 2
 

Hello everyone: I've been looking around on several forums and support pages but nobody had this problem. Here's the thing: I'm recording using all the 8 inputs on my interface and when adjusting preamp input levels with the Cubase input meters I realized that fisical input 1 level was measured by VST input 2 in the DAW and vice versa. So I checked input routing in VST Connections in case it was changed, but everything were in its place. Then I closed Cubase, turned off audio interface and reboot the laptop. Once was all turned on again, I tried to adjust levels and every fisical input was in its respective VST input. Thought it was solved until few seconds later I saw the same problem on channels 3 & 4!!! As I was only doing some sound test, I didn't worry because audio signals are fine and there's no noise or buzz. But when I need to do the definitive recording the tracks gonna be switched anywhere!
I supose that the external preamp I use on S/PDIF inputs it's guilty for this behaviour or maybe the drivers which aren't updated. Could the preamp wordclock cause this? Or drivers? Please, send me advice to do some tests.

Gear used:
ART DPSII digital preamp
M-Audio Fast Track Ultra 8x8