This was a known issue in VS 2012:
https://connect.microsoft.com/VisualStudio/feedback/details/763073/document-modified-asterisk-not-removed-when-aspx-page-modified-and-saved
It is marked as closed (fixed in VS 2013) but I experience it now in VS 2013 Update 4 (was also an issue in Update 3).
This is how it manifested itself just now: I had MyFile.aspx.cs and Myfile.aspx modified. Tab containing MyFile.aspx.cs was active. I then pressed "Save All". For the MyFile.aspx.cs tab asterisk disappeared and for Myfile.aspx it didn't. I then switched
to Myfile.aspx and asterisk disappeared for it too.
Does anyone experience the same? I didn't find Microsoft Connect issue for this.
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