Okay, I've been having problems with this grand since I received it and it didn't work at all. Sent it back and they fixed it but since then it's burning too hot. I've tried all kinds of carto's that keep getting clogged up after only 2-3 days where my other Grand will last a week. I take the carto off the New Grand and put it on the old grand and it works fine. Now the other day it I went to change the carto, again, and the delrin drip tip I use on it fused to it. There was no way me or my husband could get the tip off. Had to throw it away. What could be causing this problem? Thanks in advance for any answers.