I had to replace my 8300 over the weekend. As a result,I had to do a device swap on the BIS. Now, I don't seem to get my deleted synced between the two anymore. And yes, I do have "sync delete items" checked on the BIS.
I have both BES and BIS accounts (BES primary). Prior to the BIS 2.3 upgrade, on my gmail account I always had the option to "delete from handheld" or "delete on both", now that's gone too. Just have "delete".