I am a newbie. So, the problem is probably me. However, I have noticed that the same e-juice that I vape on one e-cig--for example the vapor 4 life--tastes fine. However, it will have a metallic taste on the provari. This doesn't happen with the pre-filled cartomizers of the same flavor. However, the juice that I purchased and arrived about 2 weeks ago does acquire this taste. I did steep the juice by leaving it open for 2 days and shaking it up. Is there something I am doing wrong? Thanks so much for your help!