the rich text editing capabilities are provided by tinyMCE, which is a widely spread and highly compatible editor and used by default for the forum software.
we could try to use another one to overcome a few issues with safari, but basically this is related to the special implementation of javascript in safari (see also http://tinymce.moxiecode.com/punbb/viewtopic.php?id=666 )
maybe the same reason is responsible for the fact, that apple websites frequently throw javascript exceptions if visited with other browsers (object expected, blabla) - also regarding this behavior i have written several times to apple without receiving any reply.
since this seems to have no priority for them i think we should not feel responsible searching for workarounds to fix bugs of software from much bigger companies ....
christian
edit: since a few years javascript is standardized as ECMA script http://www.ecma-international.org/publications/standards/Ecma-262.htm