Event Queue items remain 'In process' and cannot delete

[Michael Pokraka]

Hi,
I have an event queue here that is full of errors according to the overview screen (SWEQADM). Looking under 'linkages with errors', I managed to clear those that appeared.
This however still left over 4000 'Events with errors'. I can list these using the event browser and they show up as 'In Process'. Some of these I can spot in SM58 and kick back into action from there.
The remaining ones however are rather annoying - I cannot delete or redeliver them. Aside from trying to find out what is causing this (they've been piling up since last year), I'd like to clear them and start investigating with a clean slate. So two questions:
1) How do I get rid of them?
2) Anyone encountered a probable cause for these? ( I've spotted some other causes such as short dumps etc, but a good majority still remain a mystery)
 
Any input would be appreciated.
Cheers
Mike