Hi,
Thank you both for taking the time to reply.
I was trying to avoid a system restore, but did find another solution after much searching for one. As it seems to be a common problem I'll post it here in case it's of assistance to anybody else, but please be aware that I'm not a particularly technical type and I'm just repeating what somebody else had suggested. All I can say is that it worked for me.
Basically, changing the full and empty recycle bin icons to the opposite of what they should be (full becomes empty and empty full), clicking OK, then changing them back to what they should be has done the trick. I have no idea why this worked but the person offering this as a solution mentioned something about correction of a registry error.
