IMAC G3 400 dvd rom. with MacosX tiger wont boot!??

[macmicX]

hi! i have installed macos X tiger (before macosX panther) well its wont boot it makes start up sound but thats it it stacks blocking totaly so what to do memory i use one 64 mb second 256mb total 320mb ram.. any suggestions!! thanx and regards
macmicX

 

[ElDiabloConCaca]

Have you ever upgraded the firmware on the machine?

http://docs.info.apple.com/article.html?artnum=75430