Just to say if anyone is having problems with pops and clicks and is using a firewire audio card, the FIRST thing to do is to buy an ACTIVE Firewire repeater cable (well maybe not the first). Most of them are 4.5m. I can now get down to 3ms with no pops and clicks!!! It’s amazing how much difference this has made!!! They are about 13 quid on ebay.
Also make sure you disable wifi…
uhm… How long firewire cable did you use before you tried to amplify the signal? Would it really make a difference to buy a 4.5m extension cable to boost the signal if it just travels through a 2m cable in the first place? I could see the use of this if you need more than say… 5m of cable but otherwise the signal should be more than enough without amplification, or?
Unless your old cable was over the permissable length or had other problems, I suspect you’re misplacing the credit for the improvement. But if it popped before and it doesn’t now - who cares! Result! 
Apparently the cable is active, so it ‘rejuvinates’ the dodgy firewire signal my macbook is producing. This is the recommended fix if your computer has non TI firewire chips.
Interesting. Is it possible your old FW cable was just damaged? Have you tried a passive one other than the problem one?
Interesting indeed. If this is correct then we can all stop looking for TI chipsets when building a DAW and just buy ourselves one of those active extention cables.
So… How long was the cable you used when you experienced pops and clicks? Can you try a different non active cable that is 1-2m long to check if the pops and clicks reappear (just to make sure that it wasn’t a faulty cable you had)?
Tried many cables. I tried all sorts of things including fw800 to fw400 converters with no joy. If you go to RME’s forum there are long threads on these extenders. They have some sort of chip in them which sorts the signal out. The extender is 4.5m long, but that’s the shortest one they do. I would still deffo go for a TI chip if you can though.
Having said that, I still got some wierd glitching on my system after doing a looped vocal recording for 7 takes. I think this is because my old macbook gets too hot.
I’ve just bought a new DAW from a very cheap supplier in Watford UK, so if it turns out well, i"ll post up his details.