Vb6 - Activex Control - Code Differences

I have a group project with an ActiveX control and a test program. VB6 crashed and when I reopened the project I got some error about loading a TMP file and the program would not run. The file exists but is zero length so I assumed that was the problem. I created a copy of the ActiveX project along with a simple new test program and everything was fine. When I did the copy I also added new code with a couple of typos which I fixed and everything was fine. I then copied the ActiveX code back to the original project and the error was now gone and the program started fine.
Now for the error: When I used the new code it stopped on a line that I had made a typing error on and there was the typo. I opened the copy file and the line was correct. I checked date/time and size of the files and they were identical but the code in the IDE was different. I then checked using a test editor and the files were identical. I can of course fix the problem but my question is: why is the text in the IDE different from the text in the copy code which is where I copied it from? And how does the IDE even know there was a typo to begin with since the type was made in the copy code and corrected? Briefly the question is how can a text editor and the IDE not show the same thing?