Description:
------------
1)
$entry->getStream() returns incomplete data
or return unexpected EOF (guess)
but $entry->extract(false, $path_extract); extract valid file
Affected rar archive included in reproduce script

2) Why you package can not open remote (http) file. If remote server support HHTP_RANGE you can perform seek operations. Now a time of distributed storage :) 

Test script:
---------------
$remote_path	=	'https://dl.dropboxusercontent.com/u/73282442/Twisted_Sister-A_Twisted_Christmas-2006-MP3.r00';
		$local_path		=	sys_get_temp_dir().DIRECTORY_SEPARATOR.'buggy.rar';
		if(!file_exists($local_path)){
			copy($remote_path,$local_path);
		}

		$rar = RarArchive::open($local_path);
		$rar->setAllowBroken(true);
		
		$entries = $rar->getEntries();
		foreach ($entries as $entry){
			$name			=	$entry->getName();
			$declared_size	=	$entry->getUnpackedSize();
			$declared_crc	=	$entry->getCrc();
		
			// Copy data from a stream
			$stream			=	$entry->getStream();
			$stream_path	=	sys_get_temp_dir().DIRECTORY_SEPARATOR.'stream';
			$stream_fp		=	fopen($stream_path,'w');
			stream_copy_to_stream($stream,$stream_fp);
			$stream_size	=	filesize($stream_path);
			
			// extract file 
			$path_extract	=	sys_get_temp_dir().DIRECTORY_SEPARATOR.'extracted';
			$entry->extract(false, $path_extract); 
			$extract_size	=	filesize($path_extract);
			
			echo $name." \t Declared:".$declared_size." \t Stream:".$stream_size." Extracted:".$extract_size."\n";
			unlink($path_extract);
			fclose($stream_fp);
			unlink($stream_path);
		}

Expected result:
----------------
03-twisted_sister-white_christmas.mp3 Declared:6705696 Stream:6705696 Extracted:6705696 

Actual result:
--------------
03-twisted_sister-white_christmas.mp3 Declared:6705696 Stream:4194304 Extracted:6705696