I did my research and picked the Saffire PRO24 DSP specifically for it's features and because I wanted a Firewire interface - ostensibly for it's stability and low-latency. I was never able to get it to work without frequent, no, *constant* pops and clicks and glitches. It drove me crazy. And yes, I did all the usual trouble-shooting steps. My SiiG FW card had the recommended TI chipset. I did all the registry hacks and settings etc. No joy. 

Frustrated - I bought a Roland Quad-capture for $160. I downloaded and installed the latest drives, hooked it up, started using it. I have not had a single pop or glitch or dropout. Projects that glitched every 10 seconds play cleanly. Yay, I suppose except I still wish the Saffire worked - I really liked the preamps, I can use the 2nd headphone out and I found the VRM stuff really useful.

Oh well - playback and recording stability win out (lower latency too, over USB, go figure). 

That is all. 

well good for you ,
 
but I run  the same interface with no issues, Win 7 back to the TI driver with it, you had to run legacy drivers with XP,
 
ALSO the latest 3.1 mix control has crackle issues, some have gone back to 2.4 with solid results, I am running 3.0...

you need to list your system, maybe we can help you ..

BTW lots of Focusrite users here with no Issues...

I had a Saffire Pro 40, it worked well but had higher than I wanted latency and I did have a few Firewire problems, even with a compatibile listed T.I. Chipset in the PC.  It finally went belly up out of warranty and the estimate to fix it was within $50 of what I paid for it so I dumped it.  I had enough of Firewire so I went with an Octa-Capture (USB).  The Octa-Capture works better, has more features and lower latency.

 

Another Quad advocate here, I installed mine and have forgotten it since.
 
It just works. It works with everything I put through it and every app I use it with.
 
You'd completely hate it if you love tweaking stuff.

Are there optical connectors on those devices? You might be able to use the Saffire as a pre VIA the lightpipe. If not that is indeed a drag because the FR pres are quite nice. I'm realizing those FW Focusrites may not be the best option for Sonar.

However... there was a bad driver issue with their stuff a while back so you might want to see about updating the driver if you haven't already. Also there seem to be folks complaining about the very LATEST driver (3.1 I think) so maybe try that one then the one preceding it to see if that helps. Cheers.

I tried the 2.4 and 3.1 Saffire drivers, no difference.
I cannot find any SiiG TI firewire drivers other than what is baked into Windows 7. 
I've tried 2 other FW cards, and spent too many hours searching the interwebs, tweaking device and registry settings, all to no avail.

The Quad works great. But, I do miss the VRM feature, the 2nd headphone out and I won't claim to have Golden Ears but the Quad mic pres sound a bit harsh compared to the FR. For my stuff it will be fine. 

I'll probably sell the Saffire PRO24 DSP and the SiiG FW card as a set on e-bay. 

Have you considered the USB Scarlett series? They're pretty cheap and it should be the same mic pres. Mine works great.

Have you considered the USB Scarlett series? They're pretty cheap and it should be the same mic pres. Mine works great.

 
+1    Happy 18i6 user here.
 

I had a pro40 for a few years and it always caused me issues. Got tired of fighting with it and honestly didn't need the extra channels and picked up a quad-capture last spring and have not had one issue with it the last 8-10 months. When I move into another place and can use the extra channels I plan to pick up a octa-capture without question.

According to Maximum PC magazine earlier this year, firewire is a dying technology. USB has won the war.