Consider the following scenario.

• On a Windows Vista-based computer, you install the hotfix that is mentioned in Microsoft Knowledge Base article 932626.
• You plug in an IBM MicroDrive PCMCIA device into the computer.

In this scenario, you may notice that the MicroDrive drive letter does not appear in the Disk Management node of the Computer Management console. However, the IBM MicroDrive drive letter did appear in the console before you installed this hotfix.

In Windows Vista, an Ultra DMA Mode 5 device may perform only at the speed of an Ultra DMA Mode 2 device after you swap devices.

This problem occurs on an IBM ThinkPad mobile PC or on a Lenovo ThinkPad mobile PC if the following conditions are true:

• You start the computer with an Ultra DMA Mode 2 device in the Ultrabay swappable drive bay. For example, you start the computer with an optical drive in the drive bay.
• You eject the Ultra DMA Mode 2 device from the drive bay and insert an Ultra DMA Mode 5 device in the drive bay. For example, you insert a hard disk drive in the drive bay.

When these conditions are true, the transfer mode stays at the slower Ultra DMA Mode 2 speed. The system does not correctly use the faster Ultra DMA Mode 5 speed.