Acrobat Professional 11 Crashing while adding Notes

When working with PDF files (adding notes and saving), for a long time now, PDF crashes sometimes, with loss of work done. We have tried reinstalling windows and PDF professional but the problems still occurs at times. Is this a known bug and are there any tweaks in the settings we can do to overcome this. We have tried many things but with no solution.

PDF Professional Version : 11.014.16
Windows Version : 7

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Problem signature:

  Problem Event Name: APPCRASH

  Application Name: Acrobat.exe

  Application Version: 11.0.14.16

  Application Timestamp: 56731fe8

  Fault Module Name: Acrobat.dll

  Fault Module Version: 11.0.15.2

  Fault Module Timestamp: 56d1e418

  Exception Code: c0000005

  Exception Offset: 0075414a

  OS Version: 6.1.7601.2.1.0.256.48

  Locale ID: 1033

  Additional Information 1: 0a9e

  Additional Information 2: 0a9e372d3b4ad19135b953a78882e789

  Additional Information 3: 0a9e

  Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

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