I've been waiting for YEARS for the "specify source" feature and they still havent done it.

However, the above post is the next best thing - using preferred source on the IP route (static route) did the trick.

... so at this point in time, are there ANY STABLE pci-e 3G modems that work with the RB411 series?

I also had problems with usb 3G Modems in a RB433 and x86 machine they would have the same problem the modems would go down and have to reboot or unplug and reinsert to get them going again. Then bought a RB411U and a Sierra Wireless MC8780 miniPCI-E card a lot better then the usb dongles. never ha...