Upload Failure with large images or .zip

Hi There.

Got serious problems with uploading large images or zip-files.
What i’ve tried:

– Uploading a zip containing 3 jpgs with the max. size of 1500px and 150-400kb each. The whole zip has 848kb. failure: no error message, just a blank screen with wp-admin menue.

– Uploading on of the 1500px files – failure: no error message, but now there’s a “Create new thumbnails” bar, showing “Running… please wait” and 0% – permanently. No Data was written on the server.

– Resizing one picture to 1000px – Single upload works

– Uploading multiple 1000px files via the Flash Uploader – failure: First there is an orange upload bar, then the everlasting “Create new thumbnails” bar appears again.

– Uploading a zip containing 3 of the resized 1000px pics – failure: same blank page appears like the zip-upload mentioned first.

So what’s to do? I installed Nextgen-Gallery a couple of times before and had never any issues. As you can see so far, the only thing that works is uploading small pictures at once – and that is not an option for this special case (a photographer, that wants to upload lots and huge pictures.)

I really would appreciate some help!
thanks and love,
m.

My settings:
Wordpress 2.6.1
Nextgen-Gallery 0.98
Upload Limit: 20MByte
No other Plugins installed yet, except of All in One Seo Pack 1.4.6.13

Server Settings
* Operating System : Linux
* Server : Apache/1.3.34 Ben-SSL/1.55
* Memory usage : 9.1 MByte
* MYSQL Version : 4.0.27-max-log
* SQL Mode : Not set
* PHP Version : 4.4.9
* PHP Safe Mode : Off
* PHP Allow URL fopen : On
* PHP Memory Limit : 40M
* PHP Max Upload Size : 20M
* PHP Max Post Size : 8M
* PHP Max Script Execute Time : 50000s
* PHP Exif support : Yes ( V1.4 )
* PHP IPTC support : Yes
* PHP XML support : Yes

GD support
* GD Version : bundled (2.0.28 compatible)
* FreeType Support : Yes
* FreeType Linkage : with freetype
* T1Lib Support : No
* GIF Read Support : Yes
* GIF Create Support : Yes
* JPG Support : Yes
* PNG Support : Yes
* WBMP Support : Yes
* XBM Support : Yes
* JIS-mapped Japanese Font Support : No