would anyone know why Im getting incorrect lengths on pipe and nipples in the CADWorx BOM, for example
there are 2 nipples (100mm Lg) and the BOM states this but totals the amout to 400mm
also with pipe we have 25 Meters of pipe and the BOM is giving us a length of 47.235 Meters
any suggestions?

From the help file...

Bill of material lengths are based on DIMLFAC, DIMDEC, and DIMLUNIT.

Maybe check out your settings.

Thank-you Vanman, but thoes variables seem to be set correctly.
Im compleatly stuck on why CADWorx would be doing this
might help to say that I am using mixed metric as well

Are you certain that you don't have items overlapping exactly on top of each other?

Or - if you are extracting from a model that has the files xref'd in, look at the tree view in reference manager. With the newer versions of AutoCAD it is very easy to have the same model referenced in two or three times if it is attached (vs. overlaid) to other models.

Check out this post on disconnects: DiscontinuityView

Thank-you everyone, I ended up finding out the answer,
My employee wrote a routine that ended up placing multipliers on objects based on size and quantity, once we took that out we were getting proper sizes.

Thank-you all for your help