Problems with thumbnailImage function

[btgmarco]

The function thumbnailImage, is presenting a problem on my server, running the latest version ImageMagick 6.7.1-9 2011-11-18 Q16 with release date 2011-11-18, he is presenting the followings errors:

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MemoryAllocationFailed `' @ fatal/cache.c/AcquirePixelCache/190
Premature end of script headers: php5
---------------------------------------xxxx-------------------------------------------------
php: UnableToAcquireString `' @ fatal/string.c/AcquireString/127
Premature end of script headers: php5
---------------------------------------xxxx-------------------------------------------------
php: UnableToAcquireString `' @ fatal/string.c/AcquireString/127 (process: 20355 ): GLib - ERROR (recursed) **
gmem.c:154: failed to allocate 2032 bytes
aborting...

[notice] EACCELERATOR(20355): PHP crashed on opline 78 of thumbnailimage() at
path:388

Premature end of script headers: php5
---------------------------------------xxxx-------------------------------------------------

I´m pretty sure that memory it´s not the problem, once the server has 1GB ram memory free, and 2GB free on the SWAP memory, and 27GB on the hard disk... this system is enough to fully the requirements to resize an image with 500kb and 1024x768 , and also, I do know the problem is not the php script, because on another server the script works fine, the difference is only the version is ImageMagick 6.7.1-9 2011-08-22 Q16

I already lost two days searching for an answer to this problem , i will be very grateful with any light on this problem.

[magick]

The script is running out of memory. PHP can restrict the amount of memory a process can consume. Check your php.ini configuration file. You could force ImageMagick to process the pixels on disk by reducing the memory limits. From the command line, use '-limit memory 2MB' for example. Or use the MAGICK_LIMIT_MEMORY environment variable.