Powerbook g4 1.67hd 17"

Whenever I boot this is the error message I recieve. Any help would be great.

panic (cpu 0 caller 0x000A0A14): "mapping_remove: hw_rem_map failed - pmap = 0x2a53000, va = 0000000090000000, code = 0x194e34c2 \ n" @ / SourceCache / xnu / xnu -1228.0.2/osfmk/ppc/mappings.c: 241

Latest stack backtrace for cpu 0:

Backtrace:

0x0009AD18 0x0009B6BC 0x00029DC4 0x000A0A14 0x0009E2EC 0x0009F4E4 0x0006B8B0 0x0003AE80

0x0003C560 0x0003DBB4 0x000AFE54

Proceeding back via exception chain:

Exception state (sv = 0xe31c80)

PC = 0x00000000 , MSR = 0x0000D030; DAR = 0x00000000; DSISR = 0x00000000; LR = 0x00000000; R1 = 0x00000000; XCP = 0x00000000 (Unknown) BSD process name Corresponding to current thread: kernel_task Mac OS: 9B18 Kernel version: Darwin Kernel Version 9.1.0 : Wed Oct. 31 2007 5:48:21 p.m. PDT, root: xnu-1228.0.2 ~ 1/RELEASE_PPC