Thanks Guys - I have done plenty of searching on Google for that error - my best friend for a long time
The point is that I have a working forum on my local dev and I comment out those two modules and it dies and produces that exact error. I then have that same exact error on my Linode box and the php.ini side by side from local and live shows that the only difference is those two modules.
So if the one and only change I make is to comment out those two modules to produce exactly the same error locally - it would have to suggest that the one and only cause (?) is the lack of those two modules on my live box?
It is reproducible 100% of the time - comment them out - it dies - comment them in and it works.
UNless I'm missing something - and I probably am

- I can't see there is any other answer.