Upgraded to Yosemite - mobile broadband not working

Hi,

i have recently upgraded my iMac to Yosemite which resulted in my mobile broadband no longer working. About the dongle, it is on 3, a Huawei E3231 Hilink. What used to happen before the upgrade, the dongle (Hilink) would quickly mount and connect then disappear from the desktop, Safari would open and I would be connected to the Internet. Now, it mounts and nothing else happens.

I have searched for drivers/firmware to download from 3 and Huawei but I can't seem to find any. As this is caused by Apple I would like to think that there is a workaround. At the moment, I have this fantastic iMac that I can't use as I want to. Mobile broadband is the only option for me for a while longer.

1. Am I right in thinking that the problem is with Apple and not 3/Huawei?

2. Any suggestions to get by dongle working again?

I hope someone has a solution. Thanks!

R