Those issues you mention are strongly related to your Internet/Network Connectivity,
Please try the following steps.
Have you tried optimizing your network stack for lower latency gaming using this
Tcp/ip batch file
from speed guides?
SG TCP/IP Batch File
The SG Vista/7 TCP/IP patch us a quick way to optimize Vista TCP/IP settings for broadband internet connections.
It sets both netsh auto tunning levels and modifies the Windows Registry as recommended by our Vista Tweaks
It is recommended to run the patch when logged in with administrative priviledges.
The patch allows for reverting all settings to their respective Windows default values as well. Note you may have to right-click the link above and choose "Save Target As..." to save to your computer.
To apply, save to your desktop and run as administrator (right-click -> run as administrator). Type Y when prompted to optimize parameters.
This batch file works for Windows 7
perfectly as well.
Leatrix Latency Fix
try this Leatrix Latency Fix
that has been successfully used to lower latency in MMOs like WoW and Everquest:-
Leatrix_Latency_Fix_3.00 (use to reduce lag).zip
Network Throttling Fix
Also, just to be sure, try this registry fix
to prevent Windows from fudging up your network utilization if you're running movies/music in the background:-
(explains the phenomenon very well, this still exists in Windows 7 as a problem)
boost network game priority.zip
Unzip and run the reg file. Double click and press Yes to accept changes.
Hope that helps!