Files modified on Google Nexus 7 with Adobe Acrobat do not sync with files.acrobat.com

[nexus7new]

When I open and modify  a pdf on my Nexus 7, adding notes for example, the same file on acrobat.com does not show the changes.

If I export the file to other services like Skydrive and then open it on my PC changes are shown correctly.

Any ideas why?

[dave_m_k]

What application are you modifying your files with on your Nexus 7? 

[nexus7new]

I use Adobe Reader 10.4.2 Build 69805

[dave_m_k]

Are you opening from and saving your modified PDF file to files.acrobat.com?

[nexus7new]

As you pointed this out, I went back and did it. now it works fine, thanks.

I didn't do it before because I thought it would automatically save any changes in the original file in files.acrobat.com

Thank you for your help.