Alright, a couple of things:

1). Click on Start, click on Run, type in MSCONFIG and click on OK. On the General tab, put the bullet in Selective Startup and uncheck Load Startup Items. This will disable any programs that start during bootup (in the Run key of the registry and the Startup folders). Click OK and reboot the machine and try Cakewalk again. We're looking to see if the problem is caused by another program running in the background. (?)

Still doesn't work, go through the above procedure again and uncheck the Selective Startup bullet and reboot. (puts things back)

2). There could be a bad setting in the 'aud.ini' file found in the Cakewalk Pro Audio 9 folder. You can delete the file and start Cakewalk to create a new one, rename it to 'aud.old' and then start Cakewalk to create a new one, or open the existing file in Notepad and delete all entries after the PictureDir entry.

(cut & paste from my setup)

[Aud]
DataDir=D:\Program Files\Cakewalk\Cakewalk Pro Audio 9\WaveData
PictureDir=D:\Program Files\Cakewalk\Cakewalk Pro Audio 9\Picture Cache
PicCacheMB=20
CopyOnImport=1
ReadCache=0
WriteCache=0
ClipMix=1
VolMethod=0
PanMethod=0
DiskBufSize=64
DiskRecBufSize=64
DiskBuffers=32
Dither=1
ZeroFillMethod=2
MixScheme=0

I'm assuming you did try a reinstall. Did you delete all the folders so as to start fresh? If so, then I doubt if step #2 will make a difference since you probably did create a new file during first-time startup.

Hmmm, you gotta good one here.

-mike