pBuffer 1024x1024 problem

I have a problem with accelerated pbuffer on ati video cards with 4.xx drivers (all works fine with 3.xx)

1024x512 is ok with mipmapping
1024x1024 has picture with big big RUBBISH!
without mipmapping i have white texture

what im doing wrong?

tnx 4 help!

White suggests an invalid texture texture initialization, perhaps that texture is larger than supported by the card at your chosen format for example, or the format is incorrect or something else is wrong, look for errors after you create this texture. Garbage may be a consequence of the invalid texture.

What format is that pBuffer?