System ACE failure on ML405

I keep running into a System ACE problem on the ML405 when trying to get my own ACE file to load.

- I've properly formatted the CF card (as described in Answer Records #14456), and I've verified this by copying the demo files over and booting into them. The demos work fine, but when I select the custom ACE file from the menu, it fails and the ERR led turns on.

- I've generated the files using the genace.tcl script provided with the ml405 reference design (it contains the correct JTAG sequence for that board). I've verified that the JTAG chain setup in genace is correct (against what I read via iMPACT). I've tried using both system.bit and the ELF-infused download.bit as the basis; both fail.

- I've replaced the old genace.tcl file in \EDK\data\xmd with the new one that has the ml405's board information, and tried generating through XPS, also to no avail

- Directly from iMPACT, I created an ACE file. I tried this on a clean format of the CF, using one revision at 0, and I still got the same result.

- I'm using EDK 8.2 SP3 on Windows 2000; using a 512 MB CF disk with a

Is there anything specific in the actual bitstream that I may be missing? e.g. does my bitstream need a System ACE controller?

Thanks, Kunal