Common installation problems
First, if you get these errors while loading the module:


/lib/modules/2.4.3/kernel/drivers/usb/pwc.o: unresolved symbol kmalloc
/lib/modules/2.4.3/kernel/drivers/usb/pwc.o: unresolved symbol kfree
/lib/modules/2.4.3/kernel/drivers/usb/pwc.o: unresolved symbol printk


you forgot to turn module versioning off in your current kernel (or your Linux distribution has such a kernel installed for you). Recompile and install your kernel without this.

Second, I've received a number of error reports that unfortunately have nothing to do with my driver. The error messages look like this:


	usb.c: USB device not accepting new address=10 (error=-110) 
	hub.c: USB new device connect on bus1/1, assigned device number 12 
	usb_control/bulk_msg: timeout 
	usb.c: USB device not accepting new address=12 (error=-110) 


The key phrase in here is "device not accepting new address". When a USB device is plugged in, it gets assigned a unique bus number (the address) by the USB core; only after this succeeds the device is probed for its Vendor and Device ID and a driver is sought. But appearantly this fails, and the USB device does not accept the new address. There can be a number of causes: 

obnoxious USB controllers (the most common problem) 
power overcurrent condition (= too many devices attached) 
poor cabling 
faulty HUBs 
etc. etc. 

The long and short of it is: it has nothing to do with my driver, so please don't send me bug reports when this happens. However, there are a few things you can try out: 

Make sure all USB connectors are inserted properly; it should be seated firmly, and not wiggly. 
Plug the cam directly into the PC. 
Use powered USB hub. 
In case of a laptop, use the power supply with it. When using the battery, the voltage may drop. 
Try the latest kernel that is available, even the 2.4.0-test* and 2.5, when available. 

If this doesn't help, try the linux-usb-user mailinglist at SourceForge. Try to search the archives first. When you must mail, make sure to include a description of your hardware (motherboard, USB controller, kernel, etc).

Module load order
This isn't strictly related to the Philips Webcam modules, but it's useful information anyway. The best order in which to load your USB modules is to load all 'device' drivers first (audio, pwc, acm, scanners, etc), and finally your USB controller (usb-uhci, usb-ohci).

If you do it the other way around, you'll get spammed crazy by the USB-core with descriptor dumps because it couldn't find a driver for a particular device. The order in which you load the device drivers doesn't matter