Drag & drop text = no URL

I’ve recently begun adding text to DEVONthink Pro through drag and drop. In Safari, I’ll select text on a site and drag it to a specific folder within DTPro (either in the Groups window or the main window). Most of the time the URL will show up in the Info box, but I’ve notice there are times it does not. Haven’t figured out any pattern to it yet.

Has anyone else noticed this?

Mark

OSX 10.3.9
Safari 1.3.1 (v321.3)
Saft 7.7.2 (v218)
DTPro v.1.0