I have a Huawei E3131 3G modem and it doesn't work on latest 2012 MacBook Air. It works with older versions of OS X with USB 2.0 so it looks like the only problem is USB 3.0.
My personal experience with Huawei is that their installation app doesn't even run on a recent Mac for some reason. When I used it, I used to look into the package content to find another installation app that would actually start. If that is not the problem, please put more details.
pmjordan might be right as well as far as 32/64 bit-ness of their installation app. USB2/3 should be backward/forward compatible as per their specs as far as I know.
I solved my problem! I had the same problems with my mid-2012 MacBook Air and a Huawei 122 stick. Changed the stick to a Huawei 1221 first, then did some software upgrades, which nevertheless was helpless. Yesterday, I bought a USB 2.0 Hub (from Belkin) and everything's fine!
The guys from an Apple shop in Vienna told me that the MacBook Air starting from mid 2012 now has an unusual USB 3.0. (I can't explain in detail.)
It does seems like a problem with USB3 but to isolate it try two things: 1. Connect it to 2012 Air through USB hub 2. Connect it to a mac w/o USB3 but with OS X 10.8 onboard
It's a firmware issue. It will only connect via an USB 2.0 HUB.
Huawei has a firmware update for the modem but you won't find it anywhere. It's being distributed only via the carriers. The MobilePartner application update will not help.
There is hope.
You need "E3131Update_21.158.00.00.1020.B757.exe" and "Universal MasterCode.exe". You can search for them on Google. Or you can get them here.
The Mastercode application is required for the firmware update code. Launch it and select general huawei dongle (or don't select anything) and input your dongle IMEI. Use the software update key not the unlock key.
I got it working for my MacBook Air 2013 and MacBook Pro 2012, with 10.8 and 10.9 (Developer Preview) with this firmware update.