read dir error (readdir(): supplied argument is not a valid Directory resource )

[AFrelepypedaync]

tryin to read dir content with readdir($myDirectory), but i getting error:\[code\]readdir(): supplied argument is not a valid Directory resource \[/code\]i checked with is_dir($myDirectory) is it directory or not, and yes, it is directory.so, why i can not read dir? is it permissions problem?just to mention, it's all on win xp box, not linux.tnx in adv for your help!