I am having an issue with all versions of EWWW 1.8.x and Nextgen Gallery 2.0.40 and WP Media Library. Reverting back to EWWW version 1.7.6 resolves the issue.
I see the following oddity while managing a Nexgen Gallery.
I see the following oddity while in WP Media Library.
Here is my Debug Log
Please let me know what other information that you might need.
Thanks for a great plugin