Why are steps Skipped

[scott willeke]

All the sudden a visual build project that has been working fine for some time now just skips some steps (some are visual studio.net bulid steps, and others are subroutine steps) during the build with no indication of why the steps were skipped. If I right-click on the visual studio.NET steps and select 'rebuild selected', it says the following in the “build view” window:

Building subroutine step 'Build MyProjectsName'...
Object reference not set to an instance of an object.
Step 'Build MyProjectName' failed

If I go and immediately manually build the same project inside visual studio.net it builds fine. So my questions are:
1: I would prefer the step display a failure, rather than skipping the step. Otherwise I end up missing some assemblies during a build, and there is not an obvious indication of a build failure.
2: Why would the make visual studio .net build step fail with “object reference not set to an instance of object”.

BTW: The other subroutine step that gets skipped (the subroutine actually uses a “Replace in file step”) appears to work fine if I right-click on it and select “rebuild selected step”.

Also, no “conditional build rule” is selected. All steps in my project have the “Always build this step and child steps when checked” option selected.

Thanks in advance for any feedback.