My mum's just bought it for DD for Christmas and I have put it up this afternoon (amidst much swearing!). The problem is it seems a bit wobbly. Has anyone else had this problem? I think the little caps on the ends of the wheels might need bashing in a bit more, but not sure. It took me that long to get the blardy things in, I'm not keen on messing with them if that's not the problem. TIA