Nousername
Yes, there are problems but I'm not sure if they have solutions, for example, if the network traffic is particularly heavy you will find that your downloads behave like cars in a traffic jam. All this is also coupled with the distance you are from your connecting telephone exchange and the state of your local network infrastructure.
Obviously the above problems cannot be cured by anything you can do simply because they are outside of your control.
However, I would suggest you try TweakMaster, it may help with some of your connection/speed problems.
It is available here:
TweakMASTER - The Supreme Internet Optimizer
UK Bob