I had this same issue with squid 2.7.9.  This worked for me:

Set squid proxy to listen on port 3129 (or any port you choose, the GUI wouldn't allow me to leave it blank)
Add custom option: http_port 3128 transparent

Port forward on LAN:
Traffic TCP Src * Srcport * Dest * Destport HTTP(80) TargetIP pfsensebox IP Targetport 3128

My guess is that on the GUI without the transparent box checked, squid was not operating transparently on port 3128 until specifically defined to do so.

Unfortunately my ultimate goal was to use this rule to apply limiters to the traffic but apparently there is a bug with limiters and squid in transparent mode that I can't seem to get around!

https://doc.pfsense.org/index.php/Lightsquid_Troubleshooting

Try running Firefox on the XP box and see if that is any different.

I'll try

Clarification
the computer is old old
the operating system is old

Update from yesterday
But it was already too late and I turned off my computer

The computer in question was one hour ahead

I set the computer time and date accurate
And now

Only two sites inaccessible
And show the same message as before

f.y.i. in (somewhat) recent versions of the package its possible to create multiple 'binds' using the normal webgui options. So its possible to have 1 frontend listen on both :443(with ssl-offloading) and :80. So you don't need the bind in 'advanced pass through' anymore.

Have you looked in your SquidGuard filter log?

Hi, :)
So with ssl filtering, windows update does not want to do this. There in there a manipulation to do to solve this problem.
Sorry for my bad english  ;D

@Derelict:

Don't use transparent mode and only hosts set to use it as a proxy will use it.

Alright I will try doing that, thank you.

So what was the solution???

You are running into the application cert pinning I think, I've seen this on a few IOS/android apps but makes sense here as well, and I've confirmed that is what they are doing as well in the following link:

http://googleonlinesecurity.blogspot.com/2013/05/changes-to-our-ssl-certificates.html

At this time, Google Drive's PC application does not support SNI and performs some degree of certificate pinning for transfers.  (This is going to cause you a lot of issues with SSL MITM setups).

One fairly easy way to work around this is with a DNS based filter and with pfSense you can easily control what DNS server a client is using.

Thanks,
Adam

thanks for your response, I will look and review what you say, I'm hoping to solve this problem, otherwise im gonna give a shot with lusca.