[Plugin: Post Thumbnail Editor] Conflict with TDO mini forms plugin

First of all: this is a great plugin. Just wat I needed.
When I add a picture to a post everything works fine.

But there is a conflict when I want to crop a picture that was added by a user through the TDO mini forms plugin:
The image loads, but when I hit “Create Thumbnails”, this popup appears:
[ERROR] – Could not read imge size

I tried to set manually the file permissions to 777 and to reset the ownership, but no succes so far.
Maybe it has something to to with the different image folder :
(/wp-content/uploads/tdomf/)
Do you have any idea what this could be or where to look for ?

Thanks in advance
The debug message:

20110909 14:02:11 – [string] ===== STARTUP PHP MESSAGES =====
20110909 14:02:11 – [string] ===== SERVER LOG =====
20110909 14:02:11 – [string] [DEBUG] – PARAMETERS: Array
(
[action] => pte_ajax
[pte-action] => launch
[id] => 2192
[TB_iframe] => true
[height] => 550
[width] => 750
)

20110909 14:02:11 – [string] [DEBUG] – USER-AGENT: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
20110909 14:02:11 – [string] [DEBUG] – WORDPRESS: 3.2.1
20110909 14:02:11 – [string] [DEBUG] – SIZER: 0.62500000
20110909 14:02:12 – [string] ===== REFLOW =====
20110909 14:02:12 – [string] ===== FIXING THICKBOX =====
20110909 14:02:12 – [string] THICKBOX: 670 x 885
20110909 14:02:12 – [string] WINDOW WIDTH: 780
20110909 14:02:12 – [string] ===== REFLOW =====
20110909 14:02:12 – [string] ===== FIXING THICKBOX =====
20110909 14:02:12 – [string] WINDOW WIDTH: 780
20110909 14:02:19 – [string] ===== SETTING ASPECTRATIO: 47:26 =====
20110909 14:02:50 – [string] ===== RESIZE-IMAGES =====
20110909 14:02:50 – [object] {“id”:”2192″,”action”:”pte_ajax”,”pte-action”:”resize-images”,”pte-sizes[]”:[“large”],”x”:0,”y”:70,”w”:480,”h”:265}
20110909 14:02:51 – [string] ===== RESIZE-IMAGES SUCCESS =====
20110909 14:02:51 – [object] {“error”:[“[ERROR] – Could not read image size”],”log”:[“[DEBUG] – PARAMETERS: Array\n(\n [id] => 2192\n [action] => pte_ajax\n [pte-action] => resize-images\n [pte-sizes] => Array\n (\n [0] => large\n )\n\n [x] => 0\n [y] => 70\n [w] => 480\n [h] => 265\n)\n”,”[ERROR] – Could not read image size”]}
20110909 14:02:51 – [string] ===== SERVER LOG =====
20110909 14:02:51 – [string] [DEBUG] – PARAMETERS: Array
(
[id] => 2192
[action] => pte_ajax
[pte-action] => resize-images
[pte-sizes] => Array
(
[0] => large
)

[x] => 0
[y] => 70
[w] => 480
[h] => 265
)

20110909 14:02:51 – [string] [ERROR] – Could not read image size

http://ww.wp.xz.cn/extend/plugins/post-thumbnail-editor/