A trouble I have is that the client does not remove the spaces and line breaks that's added to sentences longer than 75 octets by default as iCal specifies.
Adding str_replace(array("\x20\xa", "\xa\x20"), "", $string) to remove them into SimpleCalDAVClient.php after it retrieves the data and before it creates with the CalDAVObject seems to do the trick for me.
I leave the issue opened just in case as this project seems abandoned.