As for the method Load, it is quite complex. But as far as EntryStream is concerned, this method reads from the stream until end of file or error. If everything was read ok, it returns true. I only use SkipEntry, if the EntryStream was not fully consumed (or else I will not be able to read archive after the error, and that doesn't mean error in archive, just some kind of inside stream format error, like unknown data).
The problem I am describing happens without calling SlipEntry method.
Everything works correctly on non-solid archives, the wrong data for the second stream and so on happens only with solid Rar.