Floor scrolling in Hexen format

I've got a problem with a map I made for Skulltag (Doom in Hexen format) - I set a few sectors to
1) Carry north fast.

2) Carry east fast.

3) Carry south fast.

4) Carry west fast.

Now, all four of them work but the flats on three of them stay completely still! However the sector carrying east scrolls right as it should! I can't work out why the other three DON'T scroll!

Please help!!

That's the "correct" behaviour. From the zdoom wiki:

225—229: Current to the East. Provide five levels of strength. Originate from Heretic.
230—244: Current. Provide five levels of strength in the North, South and West directions. Contrarily to the Eastwards current, they do not scroll, a limitation from Heretic.

You probably want to play with the Scroll_Floor linedef (223) instead. I don't know enough about it except to point you to these links:
http://zdoom.org/wiki/Scroll_Floor
http://forum.zdoom.org/viewtopic.php?f=3&t=36565
http://www.doomworld.com/vb/doom-editing/65744-annotated-boomedit-wad/

Thanks! I have no experience with ACS scripting at all, but I'll see.

You shouldn't need to script at all, scroll_floor is available as both a script and a linedef. To be clear: yes, you can use a special linedef type to control the behaviour of a sector.