Rename and "save" issues

This week I have been experiencing weird behavior. Parts or features I know I renamed have to be done once again as if info did not register first time around. Same for features I know I did at the end of a day, next morning they disappeared as if they never existed. We are two person simultaneously working in the same workspace and are experiencing a lot of slowdown this week. Is it a coincidence or due to the fact the workspace is rapidely growing in size thus heavier to refresh???