Penny, I went back to the hosting company and they - finally - came back and clarified that my site is on a single server. So in the space of 24 hours they have told me I am on a server farm and also told me I am on a single server. Is there anyway to indpendently check if I am on a single server or a server farm? Something in a HTTP  header maybe? 

All the same I am still left me with the problem of the 'remember me' cookie not working. Thanks for those links you posted and thoughts on the problem that you shared. i had come across those pages you linked during my efforts to sort this problem out and have followed thier advvice carefully, yet the problem remains. For now I'd like to first 100% confirm whether or not I am on a webfarm. Can I establish this myself somehow?

Very confusing! At this point inquiring minds want to know who you are hosting with? (and maybe why?) There is much to be said for hosting with vendors that have knowledge of and experience with DNN. Looking thru these forums you will find some names that pop up over and over.

Now to your problem, Sebastian brings a good point of whether your hoster is using web garden, if they are, I'm not sure how you can tell without asking them.