o.k. to clear it everyone, here is a short story:
at the beginning i had installed a pclinuxos2010 to my netbook and i bought the Huawei E173 usb-modem to use my sim-card from my telephone operator to browse internet and so on. One day i also bought the TP-Link WN722N usb-wifi to use where can, to save some money. and there started the problem. i couldn't use it with plos2010 so i installed plos2011 to my netbook, actualised through synaptic, made my touchpad work, installed libre office and than i localised my native language. and here was the point, when my wifi worked, but my usb-modem didn't. I tried everything but nothing worked.
so when i saw, that my system's gonna crazy from it i formated my HDD and installed the pclinuxos2011 again. this time i located it for the first, than solved the problem with my touchpad and than installed libre office. You can see, i didn't do any actualisation. and everything works like charm!
so this problem is SOLVED and how? don't do the full actualisation through synaptic. actualise only things you really need.
now i'm happy like a dog and guys: thank you for help!