How do I get Flash working under 'Standard User' (IE9, Windows 7 x64)?

I have a very irritating problem that I can't find anyone to help me  with.

In Internet Explorer 8 (and now IE9), I can view flash videos fine (Youtube, Hulu, etc).  However,  when it comes to embedded youtube flash videos on various websites, all I get is white boxes where  the video would be.  However, if I log in via my Admin user account on Windows 7 and launch  IE, the embedded video plays fine.  This issue is present in both the 32-bit and  64-bit browsers.

For the life of me, I can't figure out how to make this work with my standard  user account.  I do not want to change my account back to Administrator for  security reasons.  Let me tell you what I've done so far:

1) Uninstalled All Flashplayers using the uninstall tool as mentioned in  other articles.

2) Reinstalled using the 'Run as Administrator' option.

3) Used a slightly older version of Adobe Flash, to rule out problems with  their most recent release.

4) Ran System File Checker utility

I'm out of ideas... please assist.

Many thanks!!