It sounds like it could be a simple wicking problem. Possibly a short between coils in a dbc type device.
I would need to know a couple of things, I'm not an expert by any means but a few more pieces of information and I'll bet we can figure it out.
What kind of device are you using? If you aren't sure take a good pic of your e cig and post it. What kind of atomizer does it use? Again, if your not sure post a pic of it ( from the side please) What brand of juice is it that seems like its burning? Have you tryed changing your atomizer (if your device has a pre assembled atomizer head)? Is this the only device you have? If it is not your only device have you tryed your new juice in another device? Have you emptied your new juice out of this device and tryed your old juice in it to see if it has the same issue?
If your device uses replaceable atomizer heads, try changing it out first, when\ if you do put some juice into the atomizer directly before installing it, this will prime it and help it feed juice from your tank ( assuming you have one on your device)
Definatly do not smoke e liquid...