editing and splitting 6 channel wav files?

[sasully]

Newbie here, using v1.3.10(beta) on Windows 7 Home Premium. I have some long 6-channel interleaved wav files that I want to edit and then split into shorter 6-channel interleaved wav files.
Audacity opens the files just fine and shows 6 waveforms (tracks), but I can't figure out how to execute edits that work across all six tracks at once, e.g. excising 2 seconds out of the middle of all six. I can't even figure out how to select a segment across all six tracks; when I hold down the left click and mouse over to select a segment across tracks, it stops at four tracks for some reason. Furthermore, though I enabled the multichannel export option in edit/preferences, and can apply labels to segments of the 6ch wav, this does not allow me to 'export by label' as a set of shorter 6 channel wavs. The export is always as 2channel wavs. I don't get a channel mapping option, as I do with a plain export without splitting. (I also notice that when I save my opened 6 channel wav as a project, then reopen the project, only four tracks have content, the other two tracks are there but empty!)

So is there some way to 1) edit all 6 channels simultaneously and 2) split a 6ch file into smaller 6-ch files?

FWIW , the wav files I'm working with are 96kHz/24bit.

[steve]

Make the selection in one track, then use the up/down keys to move to another track. SHIFT+Left Click below the track name to toggle select/deselect a track. (holding the shift key down means that selected region is kept).

Use "Export Selection" to export the selected region. The channel mapping screen should pop up immediately before Export.