Load GPxPatch
Select the GpxLap tab
Uncheck the autosave option
That's what the green arrow is - autosave
In your GP4 game folder, there should be a folder called GPSaves and in there is a folder called quicksaves. That's where the autosaves go (autosave.raa, autosave.rab, autosave1.raa etc)
Don't know why it's taking 2-5 seconds. Normally it's pretty instant and doesn't usually freeze the game at all.