adding memory - 2.9v controller vs 1.8v sodimm

[j_l_b]

hi

I want to add some memory to my T61p (model 645785M) but I'm concerned that the memory controller states (using dmidecode on Ubuntu):

Memory Module Voltage: 2.9 V

while the memory module I'm considering (G.SKILLS 4GB DDR2-800 SODIMM [SQ] F2-6400CL6S-4GBSQ) states in the specs:

Test_Voltage 1.8 Volts

Am I right to be worried?  I don't want to waste my money or, even worse, damage my machine.

cheers

mark