First of all I would like to clarify a couple of things:
- VCC should be connected directly to 5v. (Ref: ElecFreaks Wiki: Pant and Touch Code -> Connect the power pins : LCD-A to 3.3V , VCC to 5V , GND to GND)
It is pretty funny that the library will tell you to put 5v to Vcc but the company puts in RED do not apply 5V.
The red text (I assume that you are refering to the red text on the ElecFreaks Wiki page) does not regard Vcc. The 3.3v signal level they are refering to is the voltage level of the I/O pins.
Then over to the originally posted issue:
I had the same problems when I added support for the ITead 4.3" and 5.0" displays to UTFT. I was originally using a shield that used resistors for level shifting. I could not figure out what was wrong.
Then I got the newer shields from ITead with the ICs instead of resistors. Then everything magically worked 
It would seem to me that the SSD1963 is not as tolerant as most other TFT controllers with regards to the I/O voltage levels.
This may be the issue with the ElecFreaks 4.3" display as well, but as I do not have one I cannot verify this (which is also the reason it is not listed in the supported displays list).
/Henning