Might just make it...

So after some conversing it seems the '12 hours' in my previous post was a fallacy - it's actually calculated over 5 days. After some hacking and optimising of the PHP scripts, the server load's dropped dramatically and it seems things might just turn out ok. Here's today's email:

Your hosting account xxxxxx has been warned due to high CPU usage - it has reached the limit allowed by your hosting plan.
Your plan is allowed to use: 4.5 % CPU average.
Your account has used: 6.41 % CPU average the last 3 days.

Close one though :)