A few days ago I did the first inking of my pen with a colour other than black. After throughly cleaning the converter on my Parker Vector pen -following guidance from the folks at gouletpens.com- I proceeded to fill it up with Waterman Tender Purple ink. All went good during the first few minutes, but after that the pen has slowly developed a tendency to skip from time to time. This didn't happened before the ink change (I was using Parker Quink black). Is this a normal occurrence or am I doing something wrong? Also, I'm planning to buy other ink brands for use with this and my other pen (Lamy Safari), should I take any precautions regarding using different brands on the same pens? Thanks!