Can't access internal CDROM sor USB Drives

I hope the moderator will forgive my posting again because I really cannot
solve this problem.

When running in Safe Mode I am able to access my internal CD and DVD drives
as well
as my USB Photo Card Reader and Pen Drive.

However when I re-boot and load up Windows XP (Home) I am only able to
access them if the same disc/card/Pen Drive has been left in the device.
Once I remove a CD etc. Windows either reports that the drive is
inaccessible or it allows me to log on to the drive but shows no files as
being present and cannot access them.

Even stranger is the fact that if I insert a music CD in a drive, Windows
Media Player opens and the music begins!

Since posting last time I have tried the following:

1) reinstalled both the CD & DVD drivers and the USB drivers & checked for
firmware updates (none)
2) removed Norton Anti-virus
3) checked the permissions
4) removed the USB hub and tried the devices directly in the pc sockets
5) scanned for viruses - none found but some spyware removed

Any other ideas?

Many thanks,

Noel