Images not working anymore after changes to DNS

Hi,

I have changed the url for my selfhosted wordpress blog. It used to only be https://www.aquarter.it , now it is additionally https://www.aquarterit.com

I changed the site url in the general settings to aquarterit.com as well – so far I have no problems accessing the site. The only thing that’s not working are the images, timthumb gives an error.

I already had a look and tried the usual troubleshooting steps:
– setting permissions on cache folder to 777,
– loading a different theme,
– deleting content of cache folder,
– updating timthumb.php with the latest code from google
– deleting the images from the media gallery and reuploading them.
– resetting the theme to default

but nothing seems to be working.

Any ideas what this could be?