problem withi image field upload

Hi i get this warnings all the time after i installed imageapi

* warning: imagecreatetruecolor() [function.imagecreatetruecolor]: Invalid image dimensions in ..\sites\all\modules\imageapi\imageapi_gd.module on line 243.
* warning: imagecolorallocate() expects parameter 1 to be resource, boolean given in ..\sites\all\modules\imageapi\imageapi_gd.module on line 267.
* warning: imagefill() expects parameter 1 to be resource, boolean given in ..\sites\all\modules\imageapi\imageapi_gd.module on line 267.
* warning: imagecopyresampled() expects parameter 1 to be resource, boolean given in..\sites\all\modules\imageapi\imageapi_gd.module on line 126.
* The page you requested does not exist. For your convenience, a search was performed using the query node function imagecreatetruecolor.