Yep, it would do, but in every case so far our monitoring info has shown that we're not causing the load spikes...it's due to other sites on our web host's server. They've just told me that the problem today was caused by a DDOS on another site, but they used the same excuse yesterday and said that they'd moved that site off our server.
Personally, I think that they've got something wrong with the set up of their webhosting environment.
Stu