Are you running any apps on the android side when messing with the FTDI device? Or just some Arduino code?
If you are running an Android app, do you have this line in your manifest?
<uses-feature android:name="android.hardware.usb.host" android:required="true"></uses-feature>
And still in the manifest, but in between the <activity></activity>
:
<intent-filter>
<action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
</intent-filter>
<meta-data android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
android:resource="@xml/device_filter" />`
Those following lines are present in my AndroidManifest.xml file to allow my app to talk to FTDI devices I'm working with currently. Again, if you aren't actually running any Android code, then disregard please! I do hope it can help though. I'm developing on a Samsung Galaxy Tab 2 7.0, in hopes of expanding to other tablets soon. So if you can get things working on the Nexus 7, I'd really appreciate knowing about the success!