Acrobat XI stops responding when applying document redactions

Very frustrated from trying multiple times to redact information from several documents.

I mark certain words for redaction.  Then I apply redactions.  The applying of the document redactions starts, but freezes/hangs within seconds of starting.

I can end the task using the task manager and when I reopen Acrobat, it gives me the option to open the previous document.

I have waited for Acrobat to apply the redactions as long as 3.5 hours with no luck.

Anyone else experience this?  Anyone have any ideas as to how to get Acrobat to apply redactions rather than hang?

Thank you,

edsager

Using:

Windows 7 64-bit

8GB DDR3 1333MHz RAM

Acrobat XI Pro