Follow these steps to see which one is causing the problem:

1. If you have the All-In-Wonder card on your system. Then disable the audio portion of it in Windows and then try Cakewalk. This can be done under Start | Settings | Control Panels | Sounds and Audio Devices | Hardware. Then, click on the ATI audio or Rage Theater Driver, choose Properties and select Do Not Use This Device (disable) at the bottom.

2. Please uninstall all non-Cakewalk audio plug-ins, or at least any Steinberg/Prosoniq ones. You'll see these plug-ins listed under Control Panel | Add/Remove Software and select the Plug-ins. Uninstall the FX plug-ins in this window, then restart Windows.

3. If that doesn't work, I suggest that you disable the "Voxware Audio Tookit" audio compression module. You'll find this under Control Panel | Multimedia | Devices tab. Click the plus-sign next to Audio Compression CODECS. Select the Voxware Audio Tookit and click Properties. Select Do Not Use in this screen and click OK. Restart Windows.

4. Locate and rename a file called AVICAP32.DLL to AVICAP32.OLD, then restart Windows.

5. If the problem contiues, then download and install the latest drivers from your soundcard manufacturer's website, or if you have the latest drivers, reinstall the ones that you have. Then, delete the files AUD.INI and TTSSEQ.INI located in your Cakewalk folder on your hard drive.

6. Try this:
a) Completely un-install Cakewalk from your computer. This is normally done from Start | Programs | Cakewalk. This will not remove any of your files or audio data.
b) To make sure nothing else is running while reinstalling Cakewalk in step 'e', choose Start | Run and type MSCONFIG. Click OK, choose Selective Startup, then uncheck the Load Startup Group Items box. Click OK, and restart Windows. You can always recheck that box at a later time. In Win 2000, click Ctrl+Alt+Del and manually End Task on the items you don't need running. Restart your computer.
c) Click the Windows Start button and select Run. At the prompt type REGEDIT and click OK. Backup your Registry before making edits - you do this by clicking the Registry menu, Export Registry File. Now delete the following Registry keys HKEY_CURRENT_USER\Software\Cakewalk Music Software HKEY_LOCAL_MACHINE\SOFTWARE\Cakewalk Music Software Please note that this will remove any effects presets and key bindings you may have made in Cakewalk. You can back up those registry keys separately if you like.
d) Delete the files AUD.INI and TTSSEQ.INI from the Cakewalk program folder.
e) Restart your computer, then reinstall Cakewalk.