I am having very often internet disconnection problem with Squid proxy service.

My server config;

OS: CentOS release 6.3 (Final)
model name  : Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
cpu MHz     : 1600.000
My Local systems IP range:192.168.2.x 
Server IP: 192.168.2.11

Also this server is configured with lamp for development,Samba SMB file service manager and No svn currently. So i see maximum possibility is this squid proxy since this is where it stops to connect and am sure when i restart the server net started working so something wrong with this squid service only.

And this server is connected with local 14 other windows machines and basically serves as a central development node.

I am able to resolve it by restarting the server fully some time or sometimes by restarting the squid proxy which is totally killing our development.

I have attached my cache log file here for the error info. Cache log file

Sample error log:

2013/07/01 13:25:38| tunnelConnectTimeout(): tunnelState->servers is NULL
2013/07/01 13:25:41| tunnelConnectTimeout(): tunnelState->servers is NULL
2013/07/01 13:25:41| tunnelConnectTimeout(): tunnelState->servers is NULL
2013/07/01 13:25:50| clientProcessRequest: Invalid Request
2013/07/01 13:26:05| tunnelConnectTimeout(): tunnelState->servers is NULL

Some help can make our lives easier, Thanks in advance.