Bro,
I tried the same method using ubuntu on my Singtel N810. I also got my Singtel N810 without contract so wanted to flash to the common firmware :
root@ubuntu:/home/phon/Desktop/n810# sudo ./flasher-3.0 -F RX-44_2008SE_2.2007.51-3_PR_COMBINED_MR0_ARM.bin -f -R

But I got this error message :
sudo: ./flasher-3.0: command not found

Appreciate all inputs how to correct the command line

Thanks.