crossdomain.xml not always downloading

I have a peculiar problem on a new FMS4 server setup, and its difficult to explain, so I apologize in advance. I've got my videos streaming out of the vod folder, and it all seems to work well with flv and mp4 versions. The captions, however, are not playing all the time. As this is a cross-domain setup, and the captions are the only resource loaded directly by the flash player (so I am told by the developer), I've tracked it down to the crossdomain.xml file not downloading to the client when they first hit the page. After a few refreshes, the crossdomain file is received, and the captions play fine.

I built FMS4.0.3 on Windows 2008 64bit, and am using the built-in Apache. I do not have this issue with my old FMS2 setup which used IIS. The Strobe player calls for the flv via rtmp, and the caption xml file via http. Every time I hit the page with a clear cache, my Google Chrome network log lists crossdomain.xml as "Pending" (status 0), and the caption bar is missing from playback. If I hit refresh 1-4 times, it will eventually download (status 200), and the captions will show up.

I've been verifying my crossdomain file contents and location which seem appropriate, but now I am not sure if it's more an FMS4 or apache configuration. Any ideas? I appreciate your consideration.

More detail...

Page on web.mydomain.com has this code:

[strobea11y height="400" weight="24.7 Mb" flv="rtmp://fms.mydomain.com/vod/video" mp4="http://fms.mydomain.com/vod/video.mp4"

captions="http://fms.mydomain.com/vod/video.xml"]

Both flv and mp4 versions of the video playback fine, with audio. It's just the captions that don't always show.

Crossdomain.xml:

<?xml version="1.0"?>

<!DOCTYPE cross-domain-policy SYSTEM "http://www.adobe.com/xml/dtds/cross-domain-policy.dtd">

<cross-domain-policy>

          <allow-access-from domain="*" />

          <site-control permitted-cross-domain-policies="all" />

          <allow-http-request-headers-from domain="*" headers="*"/>

</cross-domain-policy>

By the way, the apache access_log never shows a GET request for crossdomain.xml