Some people see it and some don't

[SteveAdams]

This one is baffling me.  I am quite the novice in working with this, know just enough to be dangerous.
Have my map up and running.

http://cusdmaps.cusd.com/flex3/index.html

Some people are able to see my layers load and other can't.  ESRI is the basemaps and I have a my livemap on top of that.  ESRI layers load but mine won't, but this is only for some people.  Others get it no problem.  I have checked to make sure they have everything updated, browsers, Flash etc.
I have taken my map data out of ArcSDE and put all of my MSD data in a FGDB.

Any thoughts on what else to check?  Thanks in advance

[DasaPaddock]

I got this security error:

SecurityError: Error #2048: Security sandbox violation: http://cusdmaps.cusd.com/flex3/index.swf cannot load data from http://cusdmaps/ArcGIS/rest/services/CUSD_Mapflex4/MapServer?f=json.

Looking at the requests, I'm unable to load:
http://cusdmaps/crossdomain.xml

[DasaPaddock]

Try changing to this in your config:

<mapservice label="CUSD Map" type="dynamic" visible="true" alpha="1.0">http://cusdmaps.cusd.com/ArcGIS/rest/services/CUSD_Mapflex4/MapServer</mapservice>

[SteveAdams]

Dasa,  THANKS!!!

I can't believe I missed that it was so obvious.  I have stared at that for weeks and didn't see it.

I still can't figure out why some people could get it and some couldn't.  Without fully qualifying our server, no one from the outside should have been able to see it.

oh well....I am thrilled its working!
Steve