When you look at the g-code editor in R-H do you see anything that describes what the printer is actually doing? If you click on Show Layer Range and leave first layer at zero. Then move last layer up one layer at a time. Does it show correctly what your hoping to print?
If it is correct I am guessing you have a bad connection or something like a thermistor is shorting out. If I'm not mistaken you just upgraded to the Bulldog XL? It just seems that a lot of people are experiencing strange problems shortly after some kind of modification. Check all your connections and if you don't have a fan on your board you should add one.
Hope this helps.
Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions