Custom urls are no longer working in D6 version for certain url patterns.

We have recently upgraded to Drupal 6, and have found an issue with custom urls for video. The Drupal 5 version of emfield worked without issue, but the Drupal 6 version of emfield/media_video_flotsam is not.

When using this url http://www.azpbs.org/as3/p/eight.swf?vidId=3436&rel=1, the video on the page is blank. Looking at the 'View Source' shows this.
<div class="emvideo emvideo-video emvideo-zzz_custom_url"></div>

In the database I can see this:
For an old Drupal5 entry
a:5:{s:37:"video_cck_zzz_custom_url_data_version";i:1;s:3:"url";s:53:"http://www.azpbs.org/as3/p/eight.swf?vidId=1997&rel=1";s:4:"size";s:5:"26023";s:4:"mime";s:29:"application/x-shockwave-flash";s:4:"type";s:3:"swf";}

For a new Drupal6 entry (notice the missing s:3:"swf"; at the end)
a:4:{s:35:"emvideo_zzz_custom_url_data_version";i:1;s:3:"url";s:53:"http://www.azpbs.org/as3/p/eight.swf?vidId=3436&rel=1";s:4:"size";s:5:"71164";s:4:"mime";s:29:"application/x-shockwave-flash";s:4:"type";}

When I updated the entry in the DB to this (notice the added a:5 and s:3:"swf";), the video appeared on the site
a:5:{s:35:"emvideo_zzz_custom_url_data_version";i:1;s:3:"url";s:53:"http://www.azpbs.org/as3/p/eight.swf?vidId=3436&rel=1";s:4:"size";s:5:"71164";s:4:"mime";s:29:"application/x-shockwave-flash";s:4:"type";s:3:"swf";}

I am wondering if the Drupal 6 version of the module is now looking only for an extension at the end of the url, and the old Drupal 5 version looked inside of the url for any type of extension?