Phantasy Star Online in Japanese Dreamcast with US modem?

Well, I have a completely legitimate problem. Hope that doesn't disqualify me for assistance. I bought an american Phantasy Star Online today, but I can't get either Utopia or the CDX loader to load it in my japanese dreamcast. I have an American modem on it, but I'm wondering if there is some kind of checking that the software does of the actual DC hardware. I also removed the bios battery to do the swap trick before the bootloaders were available. If anyone has had this problem and found a work around, please help me out. Email would be even better than posts if someone knows a sure fire fix. Thanks a lot! EvilWise