Capcom has passed along word that it's just spotted a technical glitch with the PC version of MotoGP 08 PC. Here's the statement:
Capcom regrets to inform consumers who have recently purchased the PC version of MotoGP 08 that we have just identified a technical issue with the PC version of the game. This issue only happens with MotoGP 08 PC when installing the game to a custom location on a hard drive; This issue does not affect the default installation, as it only occurs when the destination location has been changed.
To avoid this problem, please do not use the custom installation option to change the destination location for the game.
When the MotoGP 08 InstallShield Wizard reaches the step labeled "Choose Destination Location", the default installation directory will be displayed ("C:\Program Files\Capcom\MotoGP 08"). Select "Next" to continue to the next step. Do not press the "Change" button.
In the next few days, Capcom will be releasing a patch for MotoGP 08 that will correct this issue. We regret any inconvenience that this may have caused our MotoGP community.