When block syntax (getPType() 'block') allows paragraphs (getAllowedTypes() 'paragraphs'), a new paragraph will only be created when the entry syntax is followed by two new lines, like e.g.
It should create a paragraph with <pluginsyntax>content</pluginsyntax> as well, but it doesn't.
If I understand http://irclog.dokuwiki.org/index.php?d=2009-10-04#msg199980
correctly, this could be fixed easily by smuggling two EOLs into the handler - depending on circumstances.
(We probably don't need the getInternalPType() from the IRC log, but could decide upon the insertion of the EOLs by the existence of getAllowedTypes() 'paragraphs'?)