Loud pops from Focusrite 2i4 on PC start up. Is this normal ?

Focusrite advised you correctly. My Tascam US-16x08 has 'buffered' Line Outs (no pops). My PreSonus AB VSL44 popped my BX8 monitors, but good. And yes, the switches are on the back, and yes, it's a bit of a PITA to power cycle them in sequence, but I do it anyway, out of habit.
 
So, power cycle your monitors in sequence...or deal with the pops.
 
Those are, unfortunately, your only two choices. Sorry.
 
Edit: Sorry, there's a third choice. Use the Tascam. And a fourth. Buy a new Tascam US-NxN i/f.

Mettelus ... yes, even with the 2i4 monitor gain dialed down to zero they pop. I've seen the suggestion of the separate power switch elsewhere (  but thanks for the suggestion ). It's interesting how the Tascam works differently though, so I might use this on the PC ( which gets turned off and on a lot ) and use the Focusrite on my Sonar dedicated laptop.

You might want to check out this recent thread on the subject. I have the same problem with my 2i4 and I think the TC Electronic volume control could help in our situation.

http://forum.cakewalk.com...spx?m=2257832&fp=2

NEVER TURN ON ANYTHING WITH YOUR MONITORS ON.
 
rule #1.
 
 
monitors on last.

My 6i6 does the same so it's a design "flaw?" because yes, my Tascam us1641 does not pop. 
I shut my power amp off before ending my sessions,, then it's the last thing turned on when starting up. I also always turn the monitor level control all the way down. Just a habit. 
Very few powered monitors seem to have a front power swicth which is kinda dumb. But I guess a power strip or conditioner is par for the course in a real studio anyway's. 

Although I've never heard any monitors that are completely immune to pops like that, better monitors are significantly less-susceptible. My own powered speakers emit a small click if I don't turn them on last, but it's not enough that I'm concerned about damaging them. In fact, I've abused these poor monitors on several occasions by accidentally playing them WAY too loudly, and though I did fear for their safety, they weren't fazed in the least. Hey, they're German-made...
 
But I'm sure you're not considering a monitor upgrade just to solve a popping problem. Your best bet is to use a quality power strip (not the <$10 kind you get at the hardware store!). That'll give you not only the convenience of a handy power button but also some surge protection and possibly less hum.
 
I power everything in my rack from one rack-mounted power strip - except the audio interface. I turn the interface on first, before booting the computer, and turn it off last. The big front-panel switch is so much easier than reaching around the speakers and subwoofer to turn them on individually. I did have the switch fail on me once, but replacing it was easy - much easier than replacing the ones on my monitors would have been!