By default the number of devices connected to the USB host interface is limited due a memory restrition (~5 devices). This is related to all Windows Embedded CE/Compact kernel images. To solve this you need to increase the PhysicalPageSize value in registry:
[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\OHCI]
PhysicalPageSize=dword:10000 ; default value
A value of 0x40000 (256KB) should be sufficient:
