Thank you Shefinn and wpg for your responses - I was beginning to think I wouldn't get any, so it was a relief you took the time to reply.
My husband is 71, and it's only recently that I've noticed this confusion. It's so easy of course to immediately think dementia, but I shall try to bear in mind the "key test" wpg, which makes pretty good sense to me.
Like you Shefinn, my husband is on Requip (ropinirole) and takes 16mg daily, which he has done for several years now, with no problems. He sees the neurologist early September, so we'll have to ask his advice then.
Meanwhile, thank you both for your reassurances.