Problems with upload & attach to post

I tested uploading some more images.
When uploading images, the first ones uploads fast, just a few seconds. Then it seems like it stops. If I go back to “manage galleries” I can see the gallery is created and only the first image is there.

If I instead when uploading images waits after the first one, after 10 minutes suddenly all images says 100%. But I get a warning triangle on the first one saying “HTTP error”. And I get “Upload complete – 0 images were uploaded”.
In firebug I also get a error message:
[Error] Failed to load resource: the server responded with a status of 500 (Internal Server Error) (photocrati_ajax, line 0)
[Error] Failed to load resource: the server responded with a status of 500 (Internal Server Error) (photocrati_ajax, line 0)

I go back to “manage galleries” and there is one gallery for every image, so If i uploaded 10 images I have 10 galleries with one image each.

If uploading a zip-file. It uploads in a few seconds, but to get the upload complete message I have to wait for 10minutes and get HTTP error and “Upload complete-0 images were uploaded” and the same firebug error messages.
But in “manage galleries” I get one gallery with all the pictures in it.

When it comes to the “attach to post” button. If i click I first get a blank window, but waiting for 5minutes makes me get the content too. Only I only get the “headings”
For example I get “Select a display type” – but there’s nothing to choose from. Same with the other “headings”.

I get no error message here.

Operating System : Linux (64 Bit)
Server : Apache/2.2.11 (Unix) mod_mono/2.4
Memory usage : 43.15 MByte
MYSQL Version : 5.0.83-community
SQL Mode : Not set
PHP Version : 5.3.3
PHP Safe Mode : Off
PHP Allow URL fopen : On
PHP Memory Limit : 256
PHP Max Upload Size : 128M
PHP Max Post Size : 128M
PCRE Backtracking Limit : 500000
PHP Max Script Execute Time : 1600s
PHP Exif support : Yes ( V1.4 )
PHP IPTC support : Yes
PHP XML support : Yes