Top left part:
Stinky: Push lower steelbox up through pink TP. (it goes in top-left lava place)
Push upper steelbox down through TP (it goes down the black TP in Qookie's area)
Push the top-left woodbox 1 right, above the TP to block the upperside of that TP.
Qookie pushes that steelbox back up through black TP, (it will go below Stinky's pink TP) then Stinky pushes it up. The top-left lava place be ready now.
To fill the waterholes top-left, push three times a woodbox from right to left through the pink TP and follow, to push them in the water.
Bottom-left part:
Qookie pushes the lower of the 3 steelboxes in that area right over the icecurves (from R to L through black TP) Walk around to the right side and push the lower of the 2 remaining steelboxes 1 left, walk back around and push that steelbox 1 down, then right, so it goes the same way as the other one. The bottom-left lava place will be ready now.
Qookie stands below the last steelbox and slide down across the ice way to below the woodboxes. Push the leftmost box 2 tiles up, and the second box 1 up and right so it also goes through the TP, and follow to push it in the water. Repeat with the second box from the right side.
Stinky pushes the box above the pink TP to the
left, so he can go down through the TP to help Qookie with the third woodbox.
Top-right part
Loof: Push the woodbox down, but don't collect the bonuscoin. Push the lower steelbox 3 tiles right, and push the woodbox to the place where that steelbox was. Use the woodbox to trap the kaboom. Push 2 steelboxes up through the white TP.
Stinky goes back up through the black TP to the top-left area and push a woodbox right through the pink TP. It will go below the white TP in Loof's area. Loof pushes it up through the white TP and follow to push it in the water. Repeat with the other 2 boxes. Now Loof can take the bonuscoin.
Bottom-right part
Peegue pushes the rightmost woodbox right over the icecurves through the lightblue TP. Qookie pushes it out of the way. Repeat with the other box. Then Peegue should help Qookie to push the woodboxes out of the way, and to push the steelbox from left to right through the black TP. Peegue follows, and push the steelbox over the other iceway, so it will go through the lightblue TP from top to bottom.
Loof pushes the last steelbox left through the white TP, Stinky pushes it down through the pink TP, and Qookie and Peegue push it right through the black TP. Then Peegue pushes it up over the iceway.
Then Peegue and Qookie work together to push the last 3 woodboxes also right through the black TP and Peegue pushes them in the water.
Collect the coins and some hidden bonuscoins and exit.
I hope this will help. If something is not quite clear, just ask.
I was following the walkthru but somehow some of my boxes end up on top of each other 
and some are not even there in the center room...example: "make sure all the yellow X's in CRoom are filled" well, they aren't 
I know I'm doing something wrong but what? I kept repeating it over and over so I waited for a new day 
I too am having trouble with this ice cave just don't even know where to start.... 
thank you Marinus for your reply and help. I'm off to give this darn level a bashing now.(wish me luck). will let you know if i win. 
but Peeque seems to be doing really bad 