#9 imagefunctions fail

[Anonymous]

I installed the latest version of BigApache and typo3
module on a windows machine.
After creating a new page i am constantly getting errors
like this:

Warning: imagecreatefrompng()
[function.imagecreatefrompng]: 'D:/Develop/BigApache/A
pache/typo3/typo3temp/readPG_043ed23bbc8ce771e9ef
e37d2fa32bbe.png' is not a valid PNG file in
D:\Develop\BigApache\Apache\typo3\typo3
\t3lib\class.t3lib_iconworks.php on line 241

The file is actually created but seems to be not a valid
file, even the explorer preview tells me that. If I delete the
file manually, it is generated again with the same
problem.