I am currently running Autocad 2008 and when I use my pen setting assignment they all look ok until I plot. all the line types come out as one very thin line and not to the assigned thicknesses I need.
Down the bottom of the plot dialog, there is a round circle with a arrow pointing to the right. Click on this to expand the options, if not already expanded.
In the 'Plot options' section, select the 'Plot object lineweights' check box if it is available. If it is grayed out, unselect the 'Plot with plot styles' checkbox.
If you wish to use a plot style table, select the plot check box to 'Plot with plot styles'. Select the plot style table you wish to use in the selection box and then click on the pencil icon next to it. This will allow you to set various settings for each individual colour, including lineweight.
Open the Layer Properties Manager and set the lineweights there.