You have added artwork to a Work Order and have entered a dollar value into the Price field. Next, you have added a discount in the Options tab and now the artwork is discounted as well!
This is not a bug; this is expected behaviour. If you add Art to a Work Order through the Products file (using the Magnifying Glass icon), then the Art will not be discounted unless you check the box Apply also to Art.
However, if entered manually (you just type it into the Art field and the Price field), then the value of the art is lumped into the Work Order total and will be discounted.
To avoid this, create a new Product record for the art (Title or Description, Retail Price, etc). Then on the Work Order, use the Magnifying Glass icon to select the record you just created.
NOTE: The Apply also to Art checkbox is not available in FrameReady Lite. If you use the Price box in the artwork section to manually enter a price for art, then the amount of the art will be added to the amount of the Work Order in the Price tab (top right corner). Anything that affects the pricing of the work order will also affect the art, e.g. Qty, Discount, etc.
A possible solution is to either upgrade to FrameReady Standard in order to sell art or create a separate Work Order for just the art so that it will not be affected by a discount.