I have noticed that if the filename (possibly also Do Seek pin) is nill or does not link to a valid file on start of the patch, FileStream (Vaudio) will load but not play new files.
if you delete the FileStream node and use ctrl + Z to get it back, it works fine again.
see attached patch
EDIT: this is with V0.6 of the audio plugin
FileStreamLoadBug.v4p (8.6 kB)