解决办法如下(此办法是网上其他地方提出的，使用后果然可以解决以上问题)：
在index.template.html中更改一个属性，index.template.html在你的flex工程下，目录为 ：工程名\html-template\index.template.html。打开后，查看window的属性"wmode"，看到后，将其值更改为"transparent"。一般一共会有三个地方。更改完后保存，重新编译，启动工程，成功！
具体的代码如下:（注意红色字体）
<!-- saved from url=(0014)about:internet -->
<html
lang="en">
<!--
Smart developers always View Source.
This application was built using Adobe Flex, an open source framework
for
building rich Internet applications that get delivered via the
Flash Player
or to desktops via Adobe AIR.
Learn more about Flex at http://flex.org
// -->
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=utf-8" />
<!-- BEGIN Browser History required section -->
<link
rel="stylesheet" type="text/css" href="history/history.css" />
<!--
END Browser History required section -->
<title>${title}</title>
<script src="AC_OETags.js"
language="javascript"></script>
<!-- BEGIN Browser History required section -->
<script
src="history/history.js" language="javascript"></script>
<!--
END Browser History required section -->
<style>
body { margin: 0px; overflow:hidden }
</style>
<script language="JavaScript"
type="text/javascript">
<!--
//
-----------------------------------------------------------------------------
//
Globals
// Major version of Flash required
var requiredMajorVersion =
${version_major};
// Minor version of Flash required
var
requiredMinorVersion = ${version_minor};
// Minor version of Flash
required
var requiredRevision = ${version_revision};
//
-----------------------------------------------------------------------------
//
-->
</script>
<script src="../scripts/hello.js"
language="javascript"></script>
</head>
<body scroll="no">
<script language="JavaScript"
type="text/javascript">
<!--
// Version check for the Flash Player
that has the ability to start Player Product Install (6.0r65)
var
hasProductInstall = DetectFlashVer(6, 0, 65);
// Version check based upon the values defined in globals
var
hasRequestedVersion = DetectFlashVer(requiredMajorVersion, requiredMinorVersion,
requiredRevision);
if ( hasProductInstall && !hasRequestedVersion ) {
// DO NOT
MODIFY THE FOLLOWING FOUR LINES
// Location visited after installation is
complete if installation is required
var MMPlayerType = (isIE == true) ?
"ActiveX" : "PlugIn";
var MMredirectURL = window.location;
document.title = document.title.slice(0, 47) + " - Flash Player
Installation";
var MMdoctitle = document.title;
AC_FL_RunContent(
"src",
"playerProductInstall",
"FlashVars",
"MMredirectURL="+MMredirectURL+'&MMplayerType='+MMPlayerType+'&MMdoctitle='+MMdoctitle+"",
"width",
"${width}",
"height", "${height}",
"align", "middle",
"id",
"${application}",
"quality", "high",
"bgcolor",
"${bgcolor}",
"name",
"${application}",
"allowScriptAccess","sameDomain",
"type",
"application/x-shockwave-flash",
"wmode", "transparent",
"pluginspage", "http://www.adobe.com/go/getflashplayer"
);
}
else if (hasRequestedVersion) {
// if we've detected an acceptable version
transparent
// embed the Flash Content SWF when all tests are
passed
AC_FL_RunContent(
"src", "${swf}",
"width",
"${width}",
"height", "${height}",
"align", "middle",
"id",
"${application}",
"quality", "high",
"bgcolor",
"${bgcolor}",
"name",
"${application}",
"allowScriptAccess","sameDomain",
"type",
"application/x-shockwave-flash",
"wmode", "transparent",
"pluginspage", "http://www.adobe.com/go/getflashplayer"
);
} else { // flash is too old or we can't detect the plugin
var
alternateContent = 'Alternate HTML content should be placed here. '
+
'This content requires the Adobe Flash Player. '
+ '<a
href=http://www.adobe.com/go/getflash/>Get Flash</a>';
document.write(alternateContent); // insert non-flash content
}
//
-->
</script>
<noscript>
<object
classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
id="${application}"
width="${width}" height="${height}"
codebase="http://fpdownload.macromedia.com/get/flashplayer/current/swflash.cab">
<param
name="movie" value="${swf}.swf" />
<param name="quality"
value="high" />
<param name="bgcolor" value="${bgcolor}"
/>
<param name="allowScriptAccess" value="sameDomain"
/>
<embed src="${swf}.swf" quality="high"
bgcolor="${bgcolor}"
width="${width}" height="${height}"
name="${application}"
align="middle"
play="true"
loop="false"
quality="high"
allowScriptAccess="sameDomain"
type="application/x-shockwave-flash"
pluginspage="http://www.adobe.com/go/getflashplayer"
wmode="transparent">
</embed>
</object>
</noscript>
</body>
</html>
