I am having real problems with this program now. I have used Draftsight for years and noticed a year ago that it started to lock up after saves for several minutes. I thought it might be a problem with the server. Now with the paid version it seems even worse. It has become evident that even drawings hosted on the same machine are causing it problems. What seems to be the problem are the Reference Drawings. Swapping between drawings with attached Reference Drawings just causes the program to lock up. Working on a drawing with a attached Reference Drawing and, say, snapping to an element on the Reference Drawing, causes it to lock up. Has anybody else this problem and have they discovered a way of resolving it? Or is it a fundemental problem with the software?