I found in-depth reviews of the Hornes Archery Brushbow in the Dec/Jan 2007 issue of Traditional Bowhunter, the Feb/March 2007 issue of African Archer & Adventurer, and in the Bow Reports by Blacky Schwarz. The Brushbow is fairly heavy with a reflex-deflex design, a recurve style 17inch riser, a tournament specification sight window, a recurve pistol grip, and a recurve friendly brace height. The Brushbow appears to be a departure from a traditional longbow in all areas, being more akin to a recurve except for the limb tips.
I am curious as to which type of recurve you are shooting well, and how does that particular recurve differ in riser, grip, weight, etc. from your Brushbow? You may be running into issues with your basic bow set-up and tune more so than difference in bow design. If your Brushbow is set-up correctly and tuned well, I'm at a bit of a loss as to how you'd run into problems if the only difference between this and your recurve is the limb tips.
When choosing backpacks, boots, baseball bats, rifle stocks, etc.; you'll sometimes find that selected gear which works exceedingly well for some, will be a complete abysmal failure for others. Selecting a bow is no different and maybe this is what you are experiencing:)
Good Luck,
Daddy Bear