HELP: My ATI Radeon 7500 struggling ends disastrous !

[i-ubux at synass.net]

Hello Ubuntu Experts
Since 2 weeks I am struggling the Ubuntu 7.10 path as newbie
and 
am quite impressed about it ;-)

Installation went smooth !

Only:
1) Ati Radon 7500 and the Thinkpad T30 14.1" TFT screen (max
1400x1050), 
and at home in a docking station, with an external 17" TFT
screen 
(Belinea 17"TFT 17.40.10 plus 
2) static IP settings gave some headache ;-((

Today I experimented once again with the ATi & TFT screen
settings and 
landed disastrous in Nirwana !!!

Please help me ;-O

Following an instruction I noticed slight differences and 
deleted some, really not needed, resolutions and after 
rebooting I only get the beige background without any 
usable / visible result !

How do I repair this disastrous condition ?

Your step-by-step instructions are hot awaited ;-)

TIA for advice, assistance, hints & mental supports.
Cheers, svobi