I was getting the dreaded
<!-- GDE EMBED ERROR: invalid URL, please use fully qualified URL -->
error on some urls that worked fine in a browser.
After scratching my head from a while I noticed a pattern. If the url has underscores then I would get the error. I escaped the underscores and then it works fine.
http://www.vmware.com/pdf/vsphere4/r40/vsp_40_admin_guide.pdf - generated an error
http://www.vmware.com/pdf/vsphere4/r40/vsp\_40\_admin\_guide.pdf - worked!
You might want to note that or fix it in a future version.
Thanks for the plugin it comes in very handy!