I am having similar problems, just recently the programme is taking ages to load and until it launches, it blocks other applications. It used to load up in a few seconds and is now taking possibly a couple of minutes to do so. Not a problem if the computer in not needed in a hurry, I just switch on and go and make a cup of tea while it loads! Perhaps the answer is to revert to an earlier version, is there an earlier version to download anywhere? I only have 4.25 which used to work quicker. Also, don't the updates effectively build the later version?