I will admit it was a quick and dirty fix All the caches in my area seem to have their maths starting from the other end of the alphabet and they have always been using capitals. I am new to all this geocaching stuff though so don't know what the standards are for the calculations. I figured that swapping the lower case x was a reasonable default behaavior.

How about having it so that you can enter an '*' into the 'x' field in the coord calculator if it appers in a calculation to indicate that it's a multiply symbol rather than a numeric - it was what I treid to do when I discovered the problem so it's probably not a bad default behavior.