Contact Form 7 not working with jQuery 1.4?

I’m running into what looks like a compatibility issue between Contact Form 7 (version 2.1.1) and the new jQuery 1.4. CF7 works like a charm when I load jQuery 1.3.2, but whenever I switch to jQuery 1.4, pressing the “submit” button in CF7 returns the dreaded “endlessly spinning Ajax wheel with no validation message,” although the email is delivered with no problems.

This is on a site that’s in development for a client, so I can’t provide a link, but I can confirm that the page validates, and I’ve tried disabling all other plugins and all extraneous scripts to no avail.

Are there any known conflicts between CF7 2.1.1 and jQuery 1.4? Any known workarounds if so? I’ll revert to jQuery 1.3.2 for now, but I’d really like to use both if possible.

Thanks in advance for any help you can offer.

https://www.ads-software.com/extend/plugins/contact-form-7/