Resources Browser not showing images thumbnails

I've been having this issue with almost all of the sites I've built with Revolution (multiple versions).

As an editor, I use TinyMCE. While adding content, I use the editor's image button to place images. Through that feature, I usually upload images to certain directories on the server. the way I do that is:

1. Click the images button on the editor.
2. Next to Image URL field, I click the browse button. This opens the Resources Browser.
3. I select the directory to upload an image to.
4. Click the Upload Files button, which opens the upload files dialog box.
5. Click +Add button and select image from my local drive. Click Open button.
6. Click Upload button in the upload files dialog box and it uploads the file onto the server.

All goes good so far. The problem is that the images' thumbnails never display in the browser. I have many sites built with MODx Revolution and utilizing the TinyMCE editor in all of them and I think only one of the sites is displaying the thumbnails in the browser. I can't, for the life of me, figure out why that one site (it's done in 2.0.6) displays thumbnails and the others don't. Is it a feature that needs to be manually switched on (and I accidentally activated it in that one site)? Is the on/off switch for hta feature stupidly staring at me in the face?

It's making me crazy!

All my sites are on the same server.
MODx Revo (all versions starting with 2.0.6 on up)
PHP Version 5.2.10

Thank you in advance.

Hello,

Do the sites live on a temporary url with the ~ in the address, or have they launched? Do any of the config file paths have the ~ in them?

Thanks, AMDbuilder...I think that was it.

If that is the problem you can change the setting "setting_phpthumb_allow_src_above_docroot" which helps from time to time.