In 7.7 the type "mov" has been removed from types.conf so the code in Scanner/Remote.pm
Code:
	# Bug 3396, some m4a audio is incorrectly served as audio/mpeg.
	# In this case, prefer the file extension to the content-type
	if ( $url =~ /(m4a|aac)$/i && $type eq 'mp3' ) {
		$type = 'mov';
	}
Should be changed to something like 
Code:
	# Bug 3396, some m4a audio is incorrectly served as audio/mpeg.
	# In this case, prefer the file extension to the content-type
	if ( $url =~ /(aac)$/i && ($type eq 'mp3' || $type eq 'txt' ) ) {
		$type = 'aac';
	}

	if ( $url =~ /(m4a|mp4)$/i && ($type eq 'mp3' || $type eq 'txt' ) ) {
		$type = 'mp4';
	}
This handles m4a/mp4 podcasts slightly better which not only sometimes has audio/mpeg but also the "txt" MIME designation.