I've tried posting this the the Usenet groups, but haven't seen anything about it yet so I thought I'd try here. Could somebody please explain what this error means? And any possible solutions? I have some code that plots intensities on a map using Contour with an irregular grid, it was working fine about a month ago, but I haven't touched it since. Now when I run the program I get this border sort error when it gets to the Contour command. Thank you, Jeff