Customized Workspace Cannot open PDF forms anymore





I have customizaed my workspace with Flex Builder 3, Flex SDK 2 Hotfix 3. In previous months, everything is ok, and my workspace with IE 7.0 can open PDF forms inside processes. However, I do not know what is changed, my previous customized workspaces and new customized workspace can not open PDFs inside IE, but works on Mozilla Firefox. I have also tested workspace source without changing anything and deploying my server. However it still can not open PDFs, blank part is shown inside the PDF frame.

It gives an javascript error, 'undefined' is null or not an object is given

Line: 35

Character: 2

Code: 0

Error Message: 'undefined' is null or not an object

URL: http://lctk2:8080/WorkspaceTK/pdfContainer.html?Resource_78CC71E9-E28E-54CE-1451-B5E267449195&%2Fwor...

What can be the problem,

Any prompt answers will be appreciated.