This has been bugging me for a long time, I hope someone knows the answer.
Sound Forge (Sound  Forge Pro 11 version 345) always insists on opening at 44.1 kHz and I use 48kHz everywhere.
Opening the audio control in it shows that it sets my interface to 44.1kHz and the interface is locked, I can't reset it to 48kHz.
[Of course I can edit at 48kHz, but that's not the point]

 

This sounds as if your interface is locked to 44.1KHz by its own control panel. I'm guessing if you're working at 48KHz in Sonar that's not the case? Are you using the same driver mode for both? Meaning ASIO/WDM/WASAPI/MME.

I am using ASIO for both.
 
The Windows control panel for sound is set at Studio quality, 24-bit, 48K. The MixControl always shows 48kHz and I can hear the 'click' when Sound Forge starts up where it changes, but I can't make it start up in 48Khz.
 
Only Sound Forge misbehaves.
 
It's still a 32-bit app and perhaps structured for CD burning.
 
I used Procmon to trace it's startup, but I can't find anything that looks like a 44.1 K setting.

This has bugged me for years and I spent the whole morning tracing ProcMon.
 
I hope Magix updates this to 64-bit soon. It's the only 32-bit I ever seem to use.
 

If you have it play Windows sound then you won't be able to change it s alwimdows sounds are 16bit/44.1khz.

Find the setting in Windows audio preferences and turn off windows sounds and it will be fixed

I use Soundforge extensively for sample editing.  I sample everything at 96K, once I set the audio options to 96K in Soundforge, it always opens in 96K mode.

I turned off all windows sounds, and still the problem persists.
 
Soundforge will switch to whatever sample bit-depth or playback rate of the source, but it always starts up at 44.1kHz, so I get that little click on every sample rate change. The Saffire Mixcontrol is locked at 44.1kHz when this happens, but when I close Soundforge it goes back to 48kHz.
 
I'll live with that and hope Magix is working on a newer version.
 
@jimkleban - Soundforge will not allow me to change the audio settings when I choose the Saffire driver setting which makes it load its internal ASIO driver - it always insists on 44.1kHz, even though the Windows sound control panel is 48kHz. Somehow it locks the interface to that initially, but will adjust to the sample rate of the file it plays back as needed.
 
Maybe it is something to do with Firewire. That was always flakey with 32-bit apps.