The file has nearly 600,000 entities such as lines, circles, text etc. etc. on 180 Layers.

Naturally, this is going to take a while to load (about a minute on my machine) and to redraw (2 seconds on my machine). It also only takes about 15 seconds to save the file.

While working on the document, I would strongly recommend turning off the layers that you don't need and this will make redrawing a lot, lot quicker.

Also, as the file is so large, I would change the AutoSave settings as the default is that it will save a copy of the file every 5 minutes and if this takes a while, then this could be very annoying. You can change this from Tools->Preferences->Auto Save...

Hope this helps.

David Snipp
Stardraw.com Ltd