Problem is the code that inserts the "about me" block, is not correctly determining what value should go in the "block_instance.order" column. It counts the number of blocks in that row and adds 1. That would work if the contents of the "order" column are always correct, but in instances upgraded from Mahara 1.1, the values of that column are "2, 3", so the count method doesn't work because it also gives you "3".
A more robust solution is to get the maximum "order" value and add 1 to that.
Problem is the code that inserts the "about me" block, is not correctly determining what value should go in the "block_ instance. order" column. It counts the number of blocks in that row and adds 1. That would work if the contents of the "order" column are always correct, but in instances upgraded from Mahara 1.1, the values of that column are "2, 3", so the count method doesn't work because it also gives you "3".
A more robust solution is to get the maximum "order" value and add 1 to that.