VS2003 Invisibly steps through dissassembly

In VS2003, the debugger will stay on the same line for multiple presses of the F10 key, in a pattern consistent with the underliying dissaembly. Toggling the disassembly to visible, the current line moves as would be expected through the disassembly, with I believe the same number of lines/breaks that it takes to go through the code with disassembly toggled off.

Is there a way to turn off this behavior

I also have VS2005 installed. Thanks.