The pictures on a lot of websites I visit appear as a white box with a red cross in the corner. I have checked my settings and have show pictures enabled. It doesn't happen on all sites, but seems to be happening more and more. Any ideas anyone?
The red cross indicates a link to a picture, but the link is bad (i.e. the piccy doesn't exist anymore) or not accessible. It is more commonly because the picture has been moved or deleted from it's original location by the website editor, but the web page has not been updated. The problem is with the website, not your computer. Perhaps just coincidental that it "seems" to be happening more and more and is only because you've hit a few bad sites recently?
Maybe just a coincidence then. But it happens fairly regularly on sites I have been visiting for a while. Next time it happens I will post the address of the site and see if it is just me.
Try clearing out your IE cache: I know having a full cache can lead to a number of picture problems (not being able to save pictures as .jpg, for example).