FYI. I have applied GPRS update successfully according
to ways documented in this site.
In particular, I have disabled all hacks, Chinese OS, Ringo
just to be safe.

Able to use GPRS of Peoples Telecom.
Configurations are done automatically.
(i.e. don't have to type Username, Password, and APN)

However, it is quite expensive to use GPRS.
Around USD 0.01 per Kbyte