osx: strange startup thing

this morning...i turn on the machine to a dark grey screen - nothing happening...reboot...same thing...reboot...same thing...i try both holding "apple+s" and "option" down while rebooting...same thing...i try putting in the installation disk and holding "c"...same thing...nothing...

i reboot...stare at the computer...and after about 40 seconds...it goes...it starts up...

now...i'm afraid to shut down...

i did have some things in the garbage as i cleaned off one of my hard drives yesterday...but it wasn't that full...

any ever seen this before? it seems like it wasn't really a hard drive issue to me...but i don't know much...

thanks...jv

ps: oh yeah...osx 10.1.5...g4/400...lots o ram...three hard drives...os9 on a separate drive...