1. What version of ArcGIS Desktop are you using?
2. What version is your SDE geodatabase?
3. What RDBMS are you using (i.e. SQL Server 2014, Oracle 188.8.131.52)?
This sometimes occurs for me when I am using third party tools and I have an event listener listening to when I have changed my data. I will get a popup saying onChanged letting me know that the event listerner was hit.
You may want to make sure you do not have any addins or third party tools installed on your data.
Does this happen on all data or just a particular data set? If its a particular dataset it may be a feature class extension, if its all data then it may be an editing extension.