Rockstar Games has released patches resolving some of the issues
players have come across while playing online,
for both the PS3 and Xbox 360 versions of GTA IV.
The list of fixes are as follows:
* Fixed an issue where players were unable to enter or exit vehicles in GTA Race.
* Fixed an issue where scripted vehicles were causing games to unexpectedly crash.
* Improved reliability and frequency of PS3™ online leaderboard updates.
* Fixed a rare hang some players encountered when moving from a Race or GTA Race lobby into gameplay.
* Fixed a hang that would occur when players were switching teams during the countdown in the lobby.
* Fixed an issue where players were able to get ridiculously high scores from Cops 'n Crooks matches.
* Changed GTA Race and Race so that the last player remaining always receives a reward of $250.
* Fixed an issue where spectating players would prevent the game from finishing.
* Fixed an issue where players were unable to spectate in Round 2 of Cops 'n Crooks games.
* Changed countdown timer in lobby so that it no longer resets when new players join a game.
* Changed the kick option so that kicked players are no longer brought back to single player.
Source: Rockstar Social Club