Strange errors in my website error.log file

I have been browsing the error log provided by my hosting company. Most of the errors in it I can see the reason for. However I am seeing some bursts of a Recursive Include error entry where it says that when loading an already parsed page it is trying to include files which have already been included. Now I know that there are no multiple includes because 99.9% of the time it works fine when people view the site. Does anyone have any ideas as to why/how this may be happening? When it happens in the log it shows a recursive include for every included file and this repeats some 4 or 5 times.

Stuart