Of late we are having issue with users while trying to save timesheet and send timesheet for approval. On selecting these buttons the timesheet keeps on showing 'loading' message and when user clicks on any other link in PWA page a pop-up comes up 'You are naviating away from this page, your changes will be lost'.
Most the users facing this issue are either using IE 9 or IE 10 and for some users changing Browser mode to IE 9 in F12 Developer Tools worked but some users responded back saying issue still persists. But for the same users timesheet save and submit timesheet worked fine in Mozilla and Chrome browsers. Cache issue might not be present in IE as this issue happened even after clearing browser cache in IE.
The similar is issue was faced by some PMs accessing Project Center. Also there is no entry for this behavior in ULS logs.
Environment is Project Server 2010 SP2.