Hey man, Seems to me your having issues with your starter motor gears and or flywheel gears. Obviously when your engine is cold its harder to turn over and the gears grind. When you've been driving it and the engine is warm its going to be easier to turn over. This is just my thoughts dude, im no mechanic. If I were you I'd be having a look at the starter motor for its alignment with the engine. If your mechanically minded take starter off and check gears. If not I'd be gettin it to your mechanic pronto before you wreck something and are up for big bikkies. Let me know how you go. Cheers dude