I also concur and have filed bug #14724684. Specifically this appears to occur when the 'Source' value contains either <,> or ", and only when copying items as you say. I'm afraid this will not be fixed for 4.2, but we will aim to fix it for the first patch set. Interestingly, the item does still get copied despite the error, (which I'm sure you noticed anyway), but just thought I'd mention it in case that's of use to you or others as the error won't stop you from copying items containing these characters in their source.
And yes, Scott I agree with the DA copy wizard and have made a note to improve this for our next release. Thanks for mentioning it.