The latest errors are not a concern as it would not let you delete some files which may or not be allowed since your fotopost directory is 755
However your data directories to me would seem that at least those two and one are not 777
Check the thumbs, mini and medium directories under 1 and 2 as well as those directories themselves and make sure they are 777 and then do you upgrades.
Every instance of problems running the Photopost 5 upgrade that I have been witness to has been permissions related. In every case after a total recheck of all directory permissions the upgrade goes through fine
This is expecially needed to be set correctly on this upgrade as we are moving files to alternate directories.