Always better to prevent errors where possible but I don't know how to test for an empty clipboard. I suspect you could trap the error easily enough and just ignore it if it's a vba generated error.
EDIT - so there are probably more than 2 methods that I found. One is to add Forms2.0 library to your references, which can be an issue if you're distributing a front end. The other is an API call, which you don't have to write as if it were for the current version of Access because you're using 2007. However, if you upgrade or have users with different versions, code must/should be written using PtrSafe or else it will fail in newer versions. Still thinking that trapping the error is the way to go. If you're pasting records, append query or append type of code is safer and better. The downside to pasting is that user actions might interfere with the clipboard, even to the point where you end up trying to paste a picture, or as you have found, nothing.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.