I had a similar(ish) problem.
DCE ScanMagic would only work with one of my LCD monitors and only if I set the Amiga to NTSC and the display was not nice at all. Lots of vertical lines.
Picasso II with Picasso mode set would not work either with my LCD's.
Got a cheap SD/FF off ebay and all my miggies work with ALL my LCD's and even the Picasso modes seem to work fine with the LCD's too.
