My LPC-P2148 was collecting dust after the first failure under Linux and change of job mid-2006. My NForce3 AMD64 motherboard is quite picky. The thread is here and I was not able to solve the problem.
Later I found out lpcusb and jcwren's example which works fine for me. So I will start again with LPC-P2148 after some learning on the PIC USB side. Maybe I will start with modifying the lpcusb stack for bare-minimum device ( interrupt transfer, bulk transfer, generic HID like the example from LakeView Ressearch). I want to try out isochronous transfer as well as it is the base for USB audio device.
jcwren's good example
Startup Guide with Open Source Arm Development Tools
AN10583: USB Audio with libmad port and EFSL