In a blog post at tectonic that shows how to access to the internet with a 3G card through vodafone-mobile-connect-card-driver, I left a comment for those people struggling to get a permanent connection...
The instructions are found here
Here's my addition:
1. Plug in the card and restart the computer
2. On a terminal type: dir /dev/ttyUSB* and make sure you get something like this:
I found that the software seems to work perfectly only when /dev/ttyUSB0 and /dev/ttyUSB1 both refer to your 3G card. Other ttyUSB's don't seem to work for me
3. type sudo poff to make sure that all previous connections are closed. I used sudo because the vodafone-mobile-connect-card-driver-for-linux violates many permission rules when run as a normal user (the documentation told me that). Therefore sudo will grant him all the rights he needs.
4. type sudo vodafone-mobile-connect-card-driver-for-linux-debug so that you can see what’s going on. If the program seems to stop printing stuff on the terminal without having printed your contacts list yet, Try closing it and repeat steps 3 and 4.
Enjoy the web!