If it's a specially molded case around the drive ... no.
If it's the usual "lets whack a standard IDE drive in a cheap case & market it as a complete product" product that's been predominant in the last few years .. it shouldn't be a problem. But it will void your warranty, if it's still under warranty.
The USB1 vs USB2 is utter B$. The difference between the two, operational wise is the speed only.
However ... the logic of using a USB to IDE converter on an IDE drive that you've pulled out of a USB to IDE converter case totally eludes me.
The USB to IDE converter (and the case also) relies on the IDE drive working in the first place.
The only option is to plug it into the IDE & flash it.
However, if it's under warranty, the manufacturer should be able to do something with it for you.
Can you please specify what product you have?