error messages when trying to upload images

[digit-all.ru]

when I try to upload to a gallery, I get this error message:

The picture 'albums/userpics/10001/whatever.jpg' can't be inserted in the album

The image you have uploaded is corrupted or can't be handled by the GD library

Warning: imagecreatefromjpeg: 'albums/userpics/10001/whatever.jpg' is not a valid JPEG file in /home/digit-all/domains/photogallery/include/picmgmt.inc.php on line 176

GD support is "on"

GD Support enabled
GD Version 1.6.2 or higher
FreeType Support enabled
FreeType Linkage with freetype
GIF Read Support enabled
GIF Create Support enabled
JPG Support enabled
PNG Support enabled
WBMP Support enabled

what could the mistake be?  

[Casper]

Are you sure it's not corrupt.  Have you tried with other pics?
Are your jpg's saved in CMYK, not RGB.  For some reason CMYK often fail?
Are you sure they are jpg's, not gif's renamed?
What method of upload are you using?

Please provide link, and test account with upload permission.

[digit-all.ru]

1.  yes. I've tried a few different pictures from different sources
2. Ususally, I tried pics in RGB. After your comment I tried to upload a CMYK picture. didn't work.
3. sure
4. batch and step-by-step
5. link: http://photogallery.digit-all.ru username: guest password: test

thank you.

[Casper]

I tried to upload, but you have not given permission for any albums, and my group cannot have own album, so  cannot upload.
Please change the properties of at least 1 album, to allow visitors to upload, then I will try again.

[digit-all.ru]

Oops. I've made the modifications. Please, try now.

[Casper]

OK,

I tried to upload with a known good jpeg, and got the same error, 'not valid jpeg'.
I suggest you contact your host, as this seems to be a server problem.