Hi,
Thanks for your response cache, I have managed to do the bit where you say if it's a single lesson for one subject within the block, first increase the minimum number of periods, build your block so that the lesson you want on it's own is on it's own line. When you say blanks and protect the other slots, do you mean where the lesson should have been? Also when I was trying to drag it into a new slot, I was doing this by left clicking the first Colum and then dragging it on to the correct space on the bottom left timetable, the issue is every time I do this it's says there is a clash and will only let me put it there if I displace the original block.
Jen