Regarding the Trainer (Patch #4 - XLIVE 08.18.2009), Remove Wanted Status, Unlimited Amm....
Ok, I know many of you have seem to having problem with the Patch #4 - XLIVE 08.18.2009 Trainer, however I have some suggestions for you all.
#1) Update XLive correctly - Use the Windows Update to update the XLive to the latest version. Sometimes you may think you have the latest version but you don't. This will cause problems for the trainer.
#2) Activating the option correctly - Activate in the main menu, before you start the game may also help.
#3) Patching to the correct patch - Patching to the latest version will help a lot and for GTA IV it's a MUST.
Why is it so difficult to hack this game? Well because there is two version factors to consider, XLive version and GTA IV version, sometimes these two need to be the correct version (for example it says XLive 08.18.2009, Patch #4 [1.0.4]), the trainer can't do it your running an older version of XLive or an older patch.
Other games there is no debugging such as Xlive or etc. I've seen quality trainers for CoH, CoD4, CoD5 and etc. but they don't use XLive, which makes it easier for the coder to hack the game instead of dealing with them.