Flash was working just fine for me just fine until the day of this post.
I tried opening an closing flash again and it did not work.
I need help soon cause i wanted to finish my RHg demo and now i can't.

Edit: I can only make lateral and vertical lines with the paint and pencil tool. and the pen tool does nothing.

Holding SHIFT in flash makes you only able to make straight lines. Perhaps you have some weird setting on, or sticky keys or something. Try pressing shift and stuff and check then.
Also, did you try turning it off and then back on? :P

click the line tool, make sure the the drawing object icon is selected

draw the line,

click the selection tool, and deselect the line you just drew,

when away from the line, your cursor should have a tiny box at the end of it, when you move to the line, it should change to a curve,

click and bend the line in what ever curve you'd like

if that doesn't work, then your flash should be uninstalled, cache removed, and reinstalled
bye~

What you do is this. Slowly move your mouse cursor towards teh line and as it approaches the line it will change into a mouse cursor with a small curve below it, this is telling you that you can hold down the mose and drag the straight line to make it a curve, it works with both the pen tool and the straigth line tool. good luck