The same thing happens with .iml files, they switch to text view in debugging. And I am having a problem with switching back to designer view. When the debugger is running I either don't have "Edit in designer (Ctrl-T)" in the Edit menu, or I have but it doesn't do anything. I am running 603-dev1 version.
This is deliberate. Both .iml and .lay are C++ code that can be traced.
In other words, if debugger traces the code down to .lay or .iml, how would you expect to show the current location in graphical designer?