Since there are so many networking types here I thought 'd pose this problem. We have recently upgraded webhosts and in the process changed IP addresses pointing to our site. The changes were made on Saturday which was almost 5 days ago now and still the old IP address and MX records are floating about in roughly half the NS entries I've checked. The hosting service is of no help and insists everything is fine, but if that is the case, why arn't the DNS caches of these servers updating? Surely after 5 days they would all be wise to the change? Anyone know what can be done to fix this?

Thanks,
Stu