Vectra door lock broken

Hi - can anyone help, please?

The rear offside passenger door on Vectra (hatch, 1996) is permanently
locked. I can move locking catch thingy up and down - to no avail, even
though it feels as if it's doing something. Not sure whether I'm getting
the normal clonky noise from the door when operating remote locking /
unlocking cos the other 3 doors clonk so it's hard to tell; but either way,
the manual catch doesn't move up or down. Oh - and the child lock is not
set.

Any clues / links would be great - especially how to gain access, while the
door is closed, to repair whatever's broken!

TIA

 

Dunno if this is related but my drivers door occasionally stays locked and
if pushed in makes a clicky sound then with about ten minutes of fiddling
with the inside handle and the outside one (at the same time) it will open,
happens about once every two months all other doors function fine but none
will deadlock

I think in my case when im jetwashing it im spraying too much by the handle
because it seems to cause the problem. also leaving it for a day or 2 will
mean the door will open, probably the waters evaporating i dunno

Kinda embarrasing at the end of a days work everyone watches you go in the
passenger door and over the middle.. oh well

 

Thanks Jon - but does anybody here have any suggestions, please?