Too much toner

Hi all,
Suddenly my PhotoShop started to print (Canon CLC 900) with so much toner that the copier fuser could not fuse it to stick to paper, it remained like a crust (scab). Printing the same picture using other soft (PhotoDeLuxe) is OK. All settings are OK : SWOP coated, dot gain 20%, total ink limit 300%, etc. Transfer curves unmodified and linear.
I shall re-install it, but I wish to find the reason first. Any idea?
Calin
:confused:

Turn your linescreen settings down or don't print at 1200dpi. Play with your print settings.

The linescreen setting is not even active, since in the printer dialogue box it was chosen an operation mode "Full contone" that is opposite to halftone mode.
The maximum capability of this copier is 400 dpi. Even in halftone mode, I have not a large range.
But right before the damage, I have printed with a Xerox Phaser at 1200 dpi/ 150 lpi. I see no relation, but I have to think and check again.
To play with the settings is very difficult. A set of toners (special ceramic toners) costs Euro 7,000. A sheet of paper Euro 2.
Calin