Hello,
I believe it is possible. I found a forum post here that explains a similar situation. Here you can write a function for the item list and just display records that are not of a 'Discount' item type. If you follow the instructions in the post, you will get to the Formatting Rules Editor, create a new Rule Sheet and Edit the rule sheet. The formula will go in the Condition box. I'm not a Report Designer expert, so I can't help you out on developing the formula, so you will have to fiddle around with it. Remember to save it under a new name to make sure you don't override the default report.
- Greg