I've had a bug with jasper-reports from version 1.3.0 and also 1.3.1 (last working version was 1.2.8).
JDK 1.5.0_08, JDK 1.5.0_10, JDK 1.6.0 (sun)
I have a field which display the value of a String parameter. The font is Arial 24 bold.
The field was center align horizontal, works well in viewer, works well in pdf, but was right align when printing.
I've lower the font to 20 and then it works.