4 times now in 9 months or so when i've gone to start the car (my99, 61k), the starter motors made a loud grindin type noise. fine when yer try it a second later. should i be worried ?

 

Have you checked the connections on it, might need cleaning/tightning up. I'd personally get it checked out.
Cheers.
Ian.

 

You also could of stripped a tooth on the starter cog, used to get this a lot with older cars, used to give it a bash with a hammer it's as though it had jammed and it used to be ok....

 

Sounds like a dirty spindle.
The gear on the starter slides up the spindle to engage, if it gets dirty the gear will sometimes stick so the starter will just spin maybe almost engaged causing a grinding sound.
Removing the starter is an easy job, two bolts and two wires (one is live from the battery) just clean and lightly oil the spindle and replace. Job done.

Colin