grazie, ho corretto alcune cose ed ho ottenuto così quello che mi serve
`
\documentclass{beamer}
% Setup appearance:
\usetheme{Darmstadt}
\usefonttheme[onlylarge]{structurebold}
\useoutertheme{infolines}
\setbeamerfont*{frametitle}{size=\normalsize,series=\bfseries}
\setbeamertemplate{navigation symbols}{}
\usecolortheme[rgb={0.5,0,0.5}]{structure}
% Standard packages
\usepackage{pgf,pgfarrows,pgfnodes,pgfautomata,pgfheaps,pgfshade}
\usepackage{amsmath,amssymb}
\usepackage[english]{babel}
\usepackage[latin1]{inputenc}
\usepackage{times}
\usepackage[T1]{fontenc}
\usepackage{hyperref}
\usepackage{multimedia}
\usepackage{textcomp}
% Setup TikZ
\usepackage{tikz}
\begin{document}
\begin{frame}
\onslide<3>{\relax}
\alt<1-2>{
\begin{columns}
\begin{column}{5cm}
\begin{figure}
\includegraphics[scale=0.4]{PIC1}
\end{figure}
\end{column}
\begin{column}{5cm}
\begin{figure}
\includegraphics<2->{PIC2}
\end{figure}
\end{column}
\end{columns}
\begin{itemize}
\item
asdad \pause
\item
\end{itemize}
}
{fig or table goes here}
\end{frame}
\end{document}
`