Hi M, I'm an ex PlusNet user - I don't want to start a war here but after a year I really struggled to find a good reason to stay with PlusNet, and I had exactly the same issues as you. Hesitating on pages; sometimes lack of access and generally very poor internet viewing all round.
I am a light user so I had many options open to me and I choose NewNet - an instant difference; lost the stumbling; instant access to all sites viewed and the email even worked
I'm not suggesting it's all PlusNet fault but it doesn't help with their absolutely terrible customer service and lack of technical support - I would move on.
On the above mentioned: did you migrate in or were you a new connection? If the latter, you may be caught up in the five-year depreciation issue on connection and hardware!
Let us know.
Thanks - Blue