Greg, I have a serious problem on my server.... Canvas bags have a glitch where you can dupe items (I'm not sure how to do it) and I was wondering if you could add something to disable them? A guy on my server has 30 stacks of coal blocks and 5 blocks of copper... (He doesn't have any sort of mining machine and he's only been on the server for a couple days) I'll probably ban him but I want to make sure other people don't do it.
There are some Redpower tweaks floating on the net that fixes it, also Nallar's Tick Threading should fix it. Personally I hate this bug, I'm so used to feature causing dupe when used with canvas bags, that I have to regularly delete items that I duped. You can also try ShadwDrgn's recipe remover to disable crafting recipe for them.