It's true. ABS 1.0 no longer works in Leopard, even with NUTC 5.3.2 b3. It 'appears' to work, showing the correct count when I synchronize from NC to AB. However, when I open AB there is nothing there.

However, the new AB can import tab-delimited text files and NC can export tab-delimited text files so you can export from NC and import into AB. You can set up an export profile in NC, but you have to 'recreate' the import profile each time in AB. I suggest always exporting the field headers.

Finally, I got an error message and the export failed if I tried to export every field. I removed the all the custom fields (I don't use them) and it worked fine. You will have to just tinker.
Michael G. Smith, CCP
Golden Ratio Web Designs, LLC