Thanks, both. I generally find the site works fine without ebayrtm.com, whatever it might be.

However, I was beginning to wonder whether this intermittent annoyance might involve it.

Part of the problem, as I half-suspected, was that I'd blocked something with AdBlock Plus (some stylesheet, related to that irritating orange advertisement for the money back service.) At the moment, unblocking that (and simply hiding the annoyance with Element Hiding Helper) seems to be doing the trick.

Given the intermittent nature of the hassle, I'm not holding my breath. Other bits of trial and error suggest that it's not my experiments with allowing pipelining in Firefox, nor the fault of DoNotTrack or Ghostery. It'll be interesting to see what else happens.

Once again, I seem to have lost the toolbar on this window (for adding images and so on); on the plus side, I now seem to have a spell checker. Stranger and stranger.

Aern, I'd honestly be very surprised if there is any real risk of ebayrtm or any other "legitimate" part of the site harbouring nasties, but I must say I was intrigued that AVG seemed a bit suspicious. (I found that on the internet; I don't have AVG on this installation, of course.)

Let's face it, eBay/PayPal just can't afford any security slip-ups at the moment, and I'd imagine they're devoting their considerable resources to keeping things safe.

Having said that, I wonder whether they still allow third party advertisements. I'd imagine those will always represent a significant attack vector, albeit one most likely to affect folk with out of date third-party software like Flash Player or Java. In other words, probably most of us.

Edit: Oh, look. If I remember to allow Lithium, I get my toolbar back, and I can use paragraphs. Dozy? Moi?

The spell-checker seems to have vanished, though.