Sorry, forgot to mention that. The standard makefile from 0.497 Beta has Holux commented out, and compiles PSP-290 (without sound).
Also, I don't see any difference in compiling for PSP-290 and Holux that points to using either FW 1.50 or FW 3.xx OE. Is it then the PSPSDK that decides whether it'll be 1.50 or 3.xx OE compatible?
P.S.: running the EBOOT I compiled in 3.40 OE-A gave the 80020148 error, running it in 1.50 made the PSP freeze at the white screen with PSP logo.