Hi, I am new linux user, I just Installed ubuntu 9.10 on my laptop ACER ASPIRE 7535G

Specifications:
AMD Turion™ X2 Ultra dual-core mobile processor ZM-82/ ZM-84 (2 MB L2 cache, 2.20/2.30 GHz, DDR2 800 MHz, 35 W), supporting AMD HyperTransport™ 3.0 technology
4 GB of DDR2 667 MHz memory
17.3" HD+ 1600 x 900 pixel resolution,
HD3200 for running on battery(Power Express Ati feature onder Vista) and one HD4570 for running when connected to power.
Xorg 7.6 glibc 2.1
ATI Catalyst 9.12
WLAN1, 3: Acer InviLink™ Nplify™2 802.11b/g/Draft-N Wi-Fi CERTIFIED® network connection, supporting Acer SignalUp™ wireless technology
.... if you need more details please feel free to ask me

So, everything works fine except:
wireless got diconnected and after that doesn't connect anymore
Catalyst uses HD3200 and no other card identified.
the strength of the wireless signal is really poor

Can anyone help me with that? Thanx