No USB Storage Mode on GalaxyNexus running 4.2.2 I have a GalaxyNexus running Android 4.2.2

I just want to quickly backup some data files to my PC. I'm pretty sure I've done this many times before, but I guess not on this phone.

I have the Android SDK and tools installed on my PC.
I attach the phone by USB
I run monitor.bat and go to the File Explorer tab

Now, I can see and explore the file system.

I believe the folders I want to back up (like DCIM and Download) are under /storage/sdcard0
When I run a file explorer app on my phone, I see the folders under this path.
However, when I run the File Explorer from my PC I don't see the folders.

Do I have to do something to unmount the folders first before I can access them through USB? Do I have to shut off MTP and put the device in USB storage mode?

What am I missing?
Normally you would put the device into storage mode. When the phone is normally booted without storage mode you'll only be able to see internal, then when switched to storage mode you'll see the sdcard as well.

But VerizonWireless says the Galaxy Nexus doesn't come with USB storage mode. According to them you would transfer your data/files to PC across MTP. 

So having the external SD card not show in PC explorer, can be bypassed by inserting it into a card reader on the PC. A little inconvenient, but will accomplish your task.