Found a little quirk in the IDE that can add a large number of blank lines to your program.
Lets say you have a sub routine at line 1500 and you use F2 to goto that routine.
Then you delete everything from line 100 to 1500(lets say you placed it all into an include file)
Then you F2 to a new function, say line 200, and your program now ends at line 212.
When your done in that sub you hit the back arrow(see image) and it returns you to line 1500(which is not there anymore)
then press the back arrow again to return to the start of your program.
Your program will now have blank lines clear from 212 to line 1500.
in the image you can see the last line of my program is 202 but I can go back to 669. when I do then I get a bunch of blank lines from 202 to 669. and they stay until deleted. which can cause large gaps when you CTRL+END and PASTE . and as they are blank you don't even know they exist until you go looking through your code to see where a few hundred(or thousand) lines suddenly came from!