Problem to generate Thumb with 2.2.4 version

[mtgt]

Hi,

Before I used the version 1.8.6 beta, everything working well.
I tried this new version, but I can't generate thumbs anymore.
I got a lot of error.

When I go to Images in admin part, I got this message.
Fatal error: Out of memory (allocated 40108032) (tried to allocate 9792 bytes) in /home/mtgt69/public_html/botaneasite/administrator/components/com_phocagallery/helpers/phocagallery.php on line 894

and I have to stop to generate thumbs in clicking on ling to get a normal window.

In user part, I have no thumbnail, and when I click to get the normal size picture I have this error.
Warning: getimagesize(/home/mtgt69/public_html/botaneasite/images/phocagallery/Cascade/thumbs/phoca_thumb_l_fontaine 3 lements.jpg) [function.getimagesize]: failed to open stream: No such file or directory in /home/mtgt69/public_html/botaneasite/administrator/components/com_phocagallery/helpers/phocagallery.php on line 40

I check all permission on images folder, they are on 755. I turn to 777, but nothing change.

Do you have any idea where is from?

Thanks in advance for your help!

Greg