Flex/flash crashes when loading external flash using SWFLoader- VerifyError: Error #1053:

Hello
Getting a flash crash when loading external flash file using the SWFLoader
Started getting the error after upgrading the workspace to use Flex4 (Apache SDK 4.13)
And the component set is set to "MX+Spark"

Notes:
If i remove the MX+Spark and set MX only , the problem will be gone

I noticed also that if i load old flash files using the SWFLoader, i have no problem
Only newer file (AS3) make this problem

One option to look at is using ModuleLoader class
But after testing this approach , i get the same error
(VerifyError: Error #1053: Illegal override of hash in flashx.textLayout.property.EnumStringProperty.)

Tried to change the way i load the SDK libraries, instead of using "merged into code"
to use RSL - run time shared library, this does not help too

Still looking

...................

6 hours later..Solved!
SWFLoader has a property called "loadForCompatibility"
When set to "true", the loaded flash will be loaded on its own domain. Problem solved