I've had that setup boot fine from an A2091 controller, but not with KS2.04, instead with KS3.1. I'm sure you have your reasons for 2.04 vs 3.1 but some of us have more familiarity with 3.1.
Thinking about the issue, the boot process (sans GVP 3001) with KS 2.04 must recognize that the HDD is bootable and turn over controlled to its boot ROM; then with the GVP taking over booting from the KS ROM and then not recognizing it. So it comes down to the ROM code not passing the HDD as bootable to the GVP 3001. Have you checked for any ROM updates available? Does the Trump card use an RDB? Would you consider trying KS 3.1?
