Datacolor User to User Support Group.

This is my problem:
I tried to profile two different paper that are:

1) Canon Mate Photo Paper
2) Epson Premium semigloss Photo Paper
 
For both the paper I printed out and measured, with the colorimeter, n° 4 A4 targets with 729 color patches.
The profile I get for Canon paper has a strong Magenta dominant while the profile for Epson paper has a strong
yellow dominant.
To a visual inspection, under the natural light, the targets do not look clearly poor in red/magenta or yellow so to justify the dominant I get in the profiles.
I also checked on the screen if perhaps there were mistakes between the target patches and what have been measured, but also here I didn't find problems.

I'm 99% sure:
a) I printed out correctly the targets because I followed strictly what is recommended in the DataColor video titled: "Turning off 
color management: Canon 9500, Windows XP" even if I have a Canon Pixma iP6600D.
b) I calibrate my colorimeter before the measurement and  its white-base  is "immaculate"

I'm using: 
SpyderPRINT 4.2.3
Canon Pixma iP6600d with original Canon Ink
The most updated Canon driver for my printer.

Does anybody, in this forum, has suggestion/advice to overcome this problem that is driving me crazy.
Many thanks in advance for the attention.
Regards,