I'm trying to imbed Mathcad 11 blocks in VissimPE 5.0 but am getting odd system behavior. When inserting a MC block and editing it, I sometimes get a dialog box that says "Unexpected event. Save your work and restart." Other times I get something about Mathcad variable "out0" not found (when in fact is is there). I even get these errors sometimes when running the sample files that came with Vissim. I am running these products on a Dell 1.8G machine with 512Meg memory running Windows XP Home Edition. Has anyone seen similar issues? Thanks.