You could try opening the vcard file in Outlook, there is also other software out there if you google "vcard editor", find one you want and make sure there aren't any issues with the file. In this case, you could remove the offending line, save with a new name and then try to import again.
Another option, you could import your contacts into your Google account from a computer, then sync to a phone. Follow this link for help with that.
As far as other contact apps go, you will have to root your phone and install a ROM that uses a different contact system then the one that comes stock on your phone. Reason for this is most apps on the marketplace just put a different front end to the contact system already on your phone.
You could look at the marketplace and see if there is an app you like, that is a totally separate contact system from what is on the phone, but I still think this wouldn't help because your underlying issue would still exist.