Newbie- starts to cut in the air with Mach2 post processor

[carlosescuela]

hi all, I generate some Gcode with sheetcam using mach2 postprocessor, but begins to cut at 2.66 mm of the working surface, I mean in the air! I change the Postprocessor mach2plasma and performs the work in the wood(z goes up and down a lot ) using the same tool .
I read something suspicious in the gcode (mach2 post procesor)...

N0000 (Filename: ANIS.tap)
N0010 (Post processor: Mach2.scpost)
N0020 (Date: 13/08/2009)
N0030 G21 (Units: Metric)
N0040 G40 G90
N0050 F1
N0060 (Part: ANIS)
N0070 (Process: Zigzag pocket, letras, T3: Mill/router, 1,3 mm diameter, 1 mm Deep)
N0080 (Mill/router, 1,3 mm diameter)
N0090 T3 M06 G43 H3
N0100 G00
N0110 M03 S1000
N0120 X-3.1440 Y22.0594
N0130 Z3.5000
N0140 G01 Z2.0000 F500
N0150 X-4.4440
N0160 Y21.4094
N0170 X-3.7940

I'm sure it's silly for you. I've said before ....I AM NEWBIE!!!