Gentoo overscan problem

[m1d1man]

Hi everyone!
I have got Gentoo installed on my PS3 and I really like it. It goes so smooth and stable that I forget sometimes that I'm sitting not at the PC=)

The only big problem I have with it is blackborders/overscan. I tried to solve it with fbset utility according to psubuntu-dot-com manuals. But every time I try to set resolution like this:
fbset -a -xres -yres
I get error message "FBSTREAMOUTPUT error: Invalid argument". So I am confused, whether I'm doing something wrong or it's common Gentoo bug.

Also, if there is any alternative to fbset, please give a link to this)

And sorry for my eangleesh, i'm from Russia =]