The lay-out breaks when picture width is too large or when a 'word' is too long (without breaks). We have this same problem in our forum and the only sollution we could find is cutting back on image size.
This is another testforum I'm having (not the forum I was talking about, but same thing happens):
too large picture in signature:
http://doqnach.miraizou.net/cerr/phpBB2 ... ic.php?t=8
too large picture in post:
http://doqnach.miraizou.net/cerr/phpBB2 ... ic.php?t=9
It seems that as soon as the picture reaches the "quote" button, the width of the messageboard is extended, breaking the lay-out, while there is still enough space next to it. It's creating extra whitespace. (don't know how I can describe it otherwise)
I have tested it on several skins and as far as I can see it's something inherent in phpBB. Even the subsilver skin is doing this and so I don't know what can be done about it (I wish there was a solution!). Although you can't see it that well in the subsilver skin, the "quote", "edit", etc. button still shift more to the right enlarging the posting space. Right now you can only see "quote", but when it is your own post or when you are a moderator/admin this space next to the picture is even larger
That piece of javascript isn't the problem. I already erased that and it still occurs. This breaking of the lay-out does occur in at least IE and Firefox. Opera doesn't seem to be having any problems.
I hope everyone understands what I'm saying, 'cause this post seems kind of messy :-p