I've tried at least 3 different LCDs on my Picasso IV and gotten them all to work. Having said that, it does take a bit of leg work to get the PicassoIV's display timings set to your LCD's timings. I would first start with getting the manufacturer's specs for the LCD and then use the P-IV display software to adjust/test each mode.
Also there is a generic LCD profile on aminet that gives you a good starting place. Sorry I don't have the link handy.
