Very new to this...
When I add effects or play with levels or colors the preview video gets this strange pattern or grid overlayed onto it.
Is this normal? I have not tried exporting to dvd or anything else. Just want to know if its supposed to be happening.
And if so, is there a reason?
When you answer the questions that are asked in Eddie's link, also list the exact Effects, and the order that they appear in the Effects Control Panel. The order can make quite a bit of difference, though not what you describe.