[Plugin: Contact Form 7]Stuck with ‘rotating arrows’

After filling data and hitting the ‘Submit’ button part of my users experience being stuck with the ‘rotating arrows’.

Although it seems to concentrate on Windows Users using IE and therefore not a general problem (works just fine in Safari on my Mac and on Mobile Safari on my iPhone) I did try some suggestions in the FAQ and in this forum.

I’ve checked to see if disabling all other plugins fixes this, no change. Same goes for moving it from a static page to a page with posts, and for moving it out the sidebar into a post.

I’m out of ideas. Anybody suggestions for fixing this?

Regards,

Tony