Yesterday I setup a Vodem for one of the partners at our firm, for him to use on his mac. After a bit of researching on their forums, it appears that Huawei (manufacturers of the Vodem E220) are incapable of writing working drivers for the Mac, and the device is basically useless as it'll hang, randomly disconnect, flood the system-log, won't authenticate etc. etc. They really shouldn't have advertised the things as mac compatible, because they're nigh on useless on one.
I've also got one myself and until I did this research assumed it must've been something wrong with my system as it works reasonably well on a Windows PC (as long as it's in the corner of the house that gets 3G, still nowhere near the speed of the Telecom 525 cards I've tried, but perfectly usable). So currently both I, and the user are stuck with a 2 year data contract and a device that is useless for its intended purpose. (I'd actually wanted to be on the slightly more-per-month plan that didn't have the contract, but someone at VF apparently ticked the wrong box)
Has anyone tried using any of the other Vodem devices with a Mac, and if so, do they work properly? Is there likely to be any hope of me/the user being able to "trade-in" the vodem for one that is actually useful if they do in fact work?