I'm having a weird problem with images uploaded via this package, and hope someone can help!

I've uploaded some photos and images into the media section of my new 4.7.0 installation of Umbraco.  Then, in the Rich Text Editor, I insert the image and re-size it as necessary.  It appears fine - until I come to save it.  Then the image is shown as broken.  The html shows /~/media at the start, which seems to be what is breaking it.  Also, the image src url is edited to show the dimensions of the re-sized image, and there is no rel="x,y".

When I upload the same image direct to the media section by right clicking on the folder, Create, Image (i.e. not using Gecko), then I don't get these issues.

So I reckon there must be something about the way Gecko saves the images that causes the problem when we come to resize them.

To clarify further, here's the html that's returned in the RTE when I add the photos:

The photo uploaded via Gecko BEFORE Save & Publish (displays fine in the editor):

<p><img src="/media/2283/squash.jpg" alt="squash.jpg" title="squash.jpg" width="224" height="151" rel="448,301" /></p>

The photo uploaded via Gecko AFTER Save & Publish (broken):

<p><img src="/~/media/2283/squash_224x150.jpg" alt="squash.jpg" width="224" height="150" /></p>

Then, after clicking Save & Publish AGAIN (no other changes - no longer broken):

<p><img src="/media/2283/squash_224x150.jpg" alt="squash.jpg" width="224" height="150" /></p>

The photo uploaded direct to media (NOT via Gecko) BEFORE Save & Publish:

<p><img src="/media/24445/squash.jpg" alt="Squash" title="Squash" width="224" height="151" rel="448,301" /></p>

The photo uploaded direct to media (NOT via Gecko) AFTER Save & Publish:

<p><img src="/media/24445/squash.jpg" alt="Squash" width="224" height="150" rel="448,301" /></p>

It's as if the photo, when uploaded via Gecko, doesn't complete the process in the same way that adding one by one does.

Also note the difference in the media folder numbers - not sure if that's relevant?  When uploaded by Gecko, the media node ID and the media folder match (in the case above, it's 2283).  But when uploaded by the "Create" process, the node ID is 2285 but the image is stored in media folder 24445.

As we need to upload loads of images, and make this available to our client, we really need to get the Gecko process working.

Any ideas?  I'd really appreciate some help here...

Thanks
Allan