When you have a drawing where the dashed lines are not coming out dashed, there are a few things to check.
- Check the ltscale (15)
 
- Check the ltscale in the property palette of the specific object (1)
 
- Re-install the linetype.
There is also another thing to check if none of those work.  Your MSLTSCALE is probably set to 1.  change it to 0 and your linetypes should show up correctly.
This is a new variable and something we might mess with later down the road.  It is tied to annotation scales, which is another lesson.