Just thought I would add my two cents. We develop RT applications using classes that span accross different types of cRIO and PXI targets. We see all the issues mentioned here previously, along with very long load times for projects with lots of classes (LV actually loads all VIs into memory when they are in a class, when you open the project). We have resorted to using multiple projects to get around some of the issues, I tend to have one windows project, one/two development RT projects (one for PXI and one for cRIO if using both) and one build project with all the different classes of target. Although there seems to be no getting round the random broken run arrows on perfectly fine VI's. As we have multiple developers we did try using the 'seperate compiled code form source option' but this exhibited some even worse issues with some VIs not being updated on the realtime target after changes had been made (and deployed), regular deleting of the object cache seemed to be the only solution so we ended up disabling this option.