donkey kong swtlb code

when i start donkey kong i always get swt lb 0 or 4 error code
anyone help pj64 runs 1080 and goldeneye and starfox with no probs atall
my pc spec is
athlon 1ghz,256ram,nvidia geforce2mx400 64meg graphics card.
is the rom faulty or?????????
any help please coz its a great game
cheers
ROB