Copy.asmx CopyIntoItemsLocal: Value does not fall within the expected range

Question

I've a workflow in which I'm copying file from one library to a folder in another one. It is being done with calling a web service like below:

    <?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:m="http://schemas.microsoft.com/sharepoint/soap/">
  <soap:Header>
  </soap:Header>
  <soap:Body>
    <m:CopyIntoItemsLocal>
      <m:SourceUrl>WebUrl/Library/DocumentName.docx</m:SourceUrl>
      <m:DestinationUrls>
        <m:string>WebUrl/2ndLibrary/Folder/DocumentName.docx</m:string>
      </m:DestinationUrls>
    </m:CopyIntoItemsLocal>
  </soap:Body>
</soap:Envelope>

I'm getting an error below:

<CopyResult ErrorCode="Unknown" ErrorMessage="Invalid URI: The format of the URI could not be determined." DestinationUrl="/Adlib Merge Library/Test24.10_33/Test24.10_33.docx" />

What is interesting is that the same call works in 2010 SharePoint. Any ideas?

Update: Also, CopyIntoItems, on the same addresses is working fine.