This whole Omni/None thing is a mess.
When you insert soft synth, its midi track input by default is set to Omni. But, in drop-down list Omni corresponds to None.
From X3 manual (p.316)  "• None. This option actually sets the Input field to Omni. With this setting the track will record any MIDI input coming in on any enabled port (MIDI interface input driver) on any channel".
This is somewhat controversial, I think. Especially because we have another Omni option (All Inputs – Omni) that is in essence the same as Omni/None.
From X3 manual (p.316) "• All Inputs > (MIDI Omni or MIDI ch 1-16). With this setting the track will record any MIDI input coming in on any enabled port (MIDI interface input driver) on any channel, unless you choose a particular MIDI channel instead of MIDI Omni".
IMHO, to avoid confusion, None should be real None, not Omni. Given that None is actually Omni, there’s no simple way to block all inputs to track, that is sometimes desirable.
Though, I believe this theme was already discussed on forum, and still we see no changes.

The None -> Omni switcheroo is tied to the "Always Echo Current MIDI Track" option, so if you uncheck that, when you select None it will really select None and stay there.
 
However, you lose the useful feature of just clicking on a MIDI track and having your MIDI controller play into that track (the "echo=auto through" feature).
 
So yes this is a bit of a mess. I think expanding the "Always Echo Current MIDI Track" option into something like the following would work better:
 
-----------------------------------------
Default Input for New MIDI Tracks:

• [<Combo box with all available MIDI input ports, including None, Omni All, Auto and also all enabled VSTi outputs>]

 
Auto MIDI Input Port:

• [<Combo box with all available MIDI input ports, including None, Omni All and also all enabled VSTi outputs>]

-----------------------------------------
 
This way, you can set it up so that if in most cases you want None to be the input, you can do that, or you can have Auto be the default, which means when you set a MIDI track as the current track, it will set echo=through and pass MIDI events from the port selected in the second option through to that track. It also means that if you really don't want any MIDI events coming into a specific track, even when it is the current track, you can set its input to None and it will (gasp!) not have anything passed into it ever.
 
Maybe there are better solutions than the one above but what we have now is a bit wonky to say the least.

I'm wondering if this is still an issue in X3E?
Thanks...

Alex, I have a feeling it has not been fixed since I did not see anything related to it mentioned in the X3e release notes.
 
However I will confirm 100% but may only be able to do so later in the week or during the weekend. Will let you know what I find.

Thanks Steven :).

This issue used to drive me crazy with Jamstix... and I think another plugin i used before also that sent midi data out. It was annoying when in inserted a new vst and went to record and especially when I exported a file burned an audio CD and drove away only to hear my piano banging out a melodic drum rhythm... I use Jamstix to play addictive drums

Sorry for the late update... I have now confirmed that this issue still exists in X3e.

This also used to drive me crazy with Jamstix and other MIDI-out plugs. But surely, if you just get into the habit of selecting your controller instead of None/omni with every new MIDI track you create, it's not an issue?

Thanks I updated my list.

It's amazing that this is STILL not fixed.   Was it ever reported???