1. The most noticeable is that the {center} {/center} code doesn't work. It insists on putting the two codes together. If I do "center" first and then try to do "size" or something inside that, it puts the open and close "center" and then the open and close "size" -- so I tried waiting until everything was ready, blocked the whole part to be centered, and then clicked "center" -- it still puts the two codes together, not surrounding everything else. I finally gave up and I just type those codes in myself.
Well, it's not that the YaBBC codes don't do what they're supposed to (i.e. center will center text/images in a post, or size will change the size of text), it's that after clicking on a button, the code will always appear at the end of the post. That's just the way YaBB SE works in Netscape (actually, in Opera and in all browsers that use the gecko rendering engine (Netscape, Mozilla, etc.), which is why I just type them myself, too). However, you'll be happy to know that it's an issue that has been addressed in the upcoming sytem, and codes will actually be placed where you want them rather than at the end.
(I should probably also mention that this is a flaw in YaBB SE that can be traced back to IE and a programmer who didn't take the time to check his work in all browsers. The person who wrote the routine to put the YaBBC codes in posts only tested it in IE, where it works - but that's only because IE isn't W3C XHTML compliant. It doesn't work the way it should in compliant browsers like Netscape, Mozilla, etc.)
2. The Smileys - I tried to get the additional Smileys (my musicians again - I can never remember that letter and number combination!!) - a new screen came up, but it was blank, but down below it said "done." I finally had to bring up IE just to get that one darn Smiley!!!
3. The "crowdhappy" didn't jump up and down. The other things moved - beer clicked their glasses, the musicians played. I checked it in IE and they were jumping as usual.
As for these, unfortunately I have no explanation because they work fine for me. :-