With my Fast Track interface, if I'm working on a project at 44.1kHz, I can stream videos in Chrome or Firefox at the same time. The same is true with 48kHz, but I've had this occasional problem with video audio playing too fast (think Smurfs) at this sample rate. Sometimes it does, sometimes it doesn't. Don't really know what's going on there.

However if I'm working on a project at 96kHz, I can't hear any sound in videos at all. I have to close the project, close the browser, set the rate back to 44.1 and open the browser again.

I guess what I want to know is: is there any way to fix this problem, or is it just a limitation of my interface drivers? I have the setting to share drivers with other programs checked in Sonar but it doesn't help. Are there any interfaces out there which would allow me to stream videos with a project open, no matter what the sample rate of the project?

Try adjusting sample rate in the Windows control panel

   

You don't say where the video's audio is playing.
I use ASIO via my audio interface for Sonar and WDM via the motherboard sound card for everything else.
They are completely separate and neither cares about the other's sample rate. I can swap inputs via a patchbay if need be. If you absolutely must have Windows audio and Sonar audio play through the same device then do what Scook said in the previous post. But usually you will have to change the windows sample rate each time you change the Sonar sample rate so they match.
 
If you have windows system sounds playing through your audio monitors I suggest having a roll of toilet paper close at hand.The first time windows ka-chings through your monitors or phones at high volume after previewing a mix you might just need some.

I have everything going through the interface. I use headphones in the evening - if I enabled the motherboard's sound card, that means I would have to either have two sets of headphones, or switch headphones from my interface to the tower every time I wanted to switch between Sonar and a video, right? 
 
I have all system sounds turned off. 

System sounds don't matter. Just because multiple applications are using the same interface does not mean they are using the same driver. This is why I suggested looking at the windows control panel.

In the Windows control panel, the only options I have for sample rate are 44.1kHz at 16 bit, 24 bit and 32 bit. My interface however goes up to 96kHz. Any ideas why I'm only seeing 44.1 in the control panel? 

The driver that Windows uses for the interface only supports 44.1KHz sample rate.

 Hi, sharke.
 
Like the other poster, I also have my system set so that only my music production programs use the audio interface, and all standard stuff in Windows use the on-board sound, with that being set for the Windows default audio device.
 
I do not need two sets of speakers or headphones to run this way, and have two variations that both keep Windows apps using on-board sound and Sonar and such using the interface.
 
Method 1: Windows default audio device set to on-board sound.  I run a splitter out of my computer's speaker output jack - the little green one - and it splits that stereo signal into two quarter-inch mono cables, which I then feed into 2 inputs on my audio interface.  This way, the on-board sound still comes through my nice studio speakers, while not interfering with the ASIO drivers of the interface while Sonar uses that.  Both are sharing the single set of speakers.  This is the primary way I run, and it works great without me having to unplug anything to use one or the other or both at the same time.  Headphones are plugged into the audio interface headphone jack, and I can listen to the combined sounds at whatever levels of balance I wish.
 
On the rare occasion where I need those two inputs on the audio interface, I have another simple but effective way to have both sets of sounds playing at the same time, without interfering.
 
Method 2: Both display monitors I use in Sonar are HDTV's - my primary is a 46" and my secondary is a 32".  I run a single HDMI cable from my computer to the 46" HDTV, as I only use my motherboard's on-board video, so my secondary monitor gets video feed from a standard VGA cable.  SOOOO, when I need to take back those 2 inputs from the computer audio to the audio interface, I simply change the Windows Default Audio Device to be the HDMI of the primary display monitor HDTV.
 
Both approaches keep things separate - Sonar uses the ASIO drivers, and Windows uses either WDM feeds to inputs on the audio interface, or the Windows default audio device is set to the HDMI and the HDTV speakers.
 
Ta-Da.
 
Give it a shot.  The little splitter I bought is from Radio Shack, and cost me only about $5, and then the 2 standard instrument cables from the splitter to the inputs on the audio interface.  
 
I NEVER have to worry about sharing anything or about what is running at what sample rate - it all simply WORKS.  :)
 
Bob Bone

Great idea Bob, I'll definitely give that a try. I think a visit to Radio Shack is in order tomorrow (I've just recently noticed they've begun moving their stores into the 21st Century, at least here in New York!). I only have 2 inputs on my interface so it will require a bit of unplugging when I need to use those (which isn't that often really). Having said that I'm thinking about upgrading my interface to something better so maybe I'll go for more inputs this time.