Sometimes read error in getimagesize()

Sometimes display a warning error:

warning: getimagesize() [function.getimagesize]: Read error! in /home/fuerzasd/public_html/sites/all/modules/imagecache/imagecache.module on line 378.

I tried uploading the module again, flushing, changing from imagemagick to GD2 and checked the permissions: imagecache 775, subfoders (presets) 755 and images 775.

With images nothing wrong, they are proccesed and showing ok always. The only problem is the warning.

Thanks