should I be worried

[rsvp]

Have just logged on - all is normal except when I went to 'last' post on one thread I got a half black screen. Chose a random thread and clicked on to get a fragmented black, picasso like pattern - the last one was definitely a post from ratter (big dogs) and I'm pretty sure the first one was too.

[rsvp]

have just discovered another thread about this so apols for double posting.