Having similar issues with the Web Clipper on Firefox. Especially when clipping a PDF.
It is actually more productive to:
Download the PDF.
Send it directly. to the native Evernote application.
Delete the downloaded PDF.
I believe it's an upload bandwidth utilization issue.
The process using the Web Clipper takes far longer than using the download & send method with the native application.
Conclusions: The native Evernote Application utilizes upload bandwidth more efficiently than the Web Clipper.
