Cannot save to microSD card in connected device from Firefox

[mythbuntubox]

Odd problem:

The fastest way to transfer MythTV recordings to the microSD card of my mobile device is to connect it directly to the Mythbuntu box using the USB cable. For this, I tried to open Firefox, then the Mythweb page, locate the programme I want to download and press the direct download link and select the connected mobile device that is already mounted and can be written to just fine with Thunar. However, in Firefox, an error message pops up that the device cannot be opened because it is "not local". This seems to be Mythbuntu (maybe 14.04) specific, as I can save just fine from Firefox to the same device and microSD card under normal Ubuntu (14.04). MTP is being used for this. Any ideas on how to solve this?

TIA

[wesnewell]

I run mythbuntu 14.04. Everything worked fine here, after setting both firefox and chromes download settings to ask where to save the files.
wes@mythfe0:/media/wes/48C6-F683$ ls
Basic.mpg Red Eye.mpg

[mythbuntubox]

Hmm, curious. I appreciate you trying it out at your end, wesnewell. That at least gives me hope that it should be able to work correctly somehow.