Yes, you can cancel a pre-ordered game on Steam as long as you cancel before the release date of the game in question.

When researching this, it appears the trojan is "infostealer.gampass".

Infostealer.Gampass is a generic detection for a Trojan horse that steals online game accounts, such as Lineage, Ragnarok online, Rohan, and Rexue Jianghu. Also, a few antivirus websites indicate some of the variations of this trojan can have a keylogger embedded in it. With that in mind, I would hate to have any of the passwords to my accounts/games/websites stolen.

Using Norton Antivirus 2002 I also detected a VIRUS on Gamespot.

This is the link I got the virus at and my logfile.

http://www.gamespot.com/pc/action/jointoperations/review.html?om_act=convert&om_clk=gssummary&tag=summary;review

Date: 4/2/2007, Time: 0:08:26, user on USER
The file
C:\WINDOWSmppds.exe
is infected with the Infostealer.Gampass virus.
Unable to repair this file.

Date: 4/2/2007, Time: 0:08:26, user on USER
The file
C:\WINDOWSmppds.exe
is infected with the Infostealer.Gampass virus.
Access to the file was denied.

The file
C:\Documents and SettingsmynameLocal SettingsTemporary Internet FilesContent.IE54H2R8HMZa[1].exe
is infected with the Infostealer.Gampass virus.
Unable to repair this file.

Date: 4/2/2007, Time: 0:23:34, user on USER
The file
C:\Documents and SettingsmynameLocal SettingsTemporary Internet FilesContent.IE54H2R8HMZa[1].exe
is infected with the Infostealer.Gampass virus.
Access to the file was denied.

According to the readme for the 1.1 patch:

[Changing Screen Resolutions]
You can change the screen resolution using the SCREEN option in GAME OPTIONS.

Please note that the maximum resolution depends on your monitor

What is your monitor resolution and what resolution are you trying to change it in the game to? My guess is that since you are crashing each time you change it, you are changing it to an unsupported monitor resolution.