If I install GRML 2010.04 to the second partition of an USB stick, using 
GRML2USB 0.9.27 and boot it in a i386 machine, the following happens:

Syslinux gives error messages "vesamenu.c32: not a COM23R image" in regular 
intervals. But at least there get a "boot: " prompt, which boots "grml".

If I try to boot "hdt" syslinux gives a similar error: "/boot/addons/hdt.c32: 
not a COM32R image". The same is true for "bsd", while "dos" boots for some 
reason.

Strangely, the F1..F10 keys are not working (no error message) either, until I 
enter "help".

Not much information but if you may tell me how to provide more, I'll do.