Other people are having a problem with the new notification change seemingly it is to do with the 1.5.1 upgrade to 1.5.2 and not a fresh install of 1.5.2. What has happen here the cron message the it needs to be set right has made clients thinking the original url that worked fine needs to be change and as you know Michael it does not need changing. It was a software bug thus the 1.5.3 upgrade.
basically if Kaptain has changed his cron path he needs to change it back to the original.
His problem with the notifications is not due to a cron path problem. Its some other issue for sure