Missing paragraphs in glossary

Question

After each abbreviation there is a paragraph in my glossary except in one row. (see screenshot). There is no separation between the "W3C" and "WHATWG" abbreviation.

Does anyone know what I can do?

This is my code:

% Glossary package
\usepackage{datatool}
\usepackage[ngerman]{translator}
\usepackage[nopostdot,nonumberlist,acronym,toc,section]{glossaries}

\makeglossaries

% Abbreviations
\newacronym{html}{HTML}{Hypertext Markup Language}
\newacronym{cern}{CERN}{Conseil Européen pour la Recherche Nucléaire}
\newacronym{w3c}{W3C}{World Wide Web Consortium}
\newacronym{sgml}{SGML}{Standard Generalized Markup Language}
\newacronym{xml}{XML}{Extensible Markup Language}
\newacronym{ie9}{IE9}{Internet Explorer 9}
\newacronym{xhtml}{XHTML}{Extensible HyperText Markup Language}
\newacronym{dtd}{DTD}{Dokumenttypdefinition}
\newacronym[longplural=Rich Internet Applications]{ria}{RIA}{Rich Internet Application}
\newacronym{ajax}{AJAX}{Asynchronous JavaScript and XML}
\newacronym{whatwg}{WHATWG}{Web Hypertext Application Technology Working Group}
\newacronym{swf}{SWF}{Small Web Format}

% Output
\cleardoublepage{}

\printglossary[style=altlist,title=Glossar]

\deftranslation[to=German]{Acronyms}{Abkürzungsverzeichnis}
\printglossary[type=\acronymtype,style=long]

Answer 1

Your acronym list is based on longtable, and is a grouped style. The groups are separated by an empty row in the longtable. To get rid of that row, we define a new style based on long:

\newglossarystyle{mylong}{%
  \glossarystyle{long}%
  \renewcommand{\glsgroupskip}{}
}

This shall be put in the preamble after loading glossaries. To use it, issue

\printglossary[type=\acronymtype,style=mylong]

Answer 2

If you have a recent version of glossaries you can use the nogroupskip package option to suppress the gap between letter groups.

\usepackage[nogroupskip]{glossaries}