Your problem is probably that you just can't add Hunter's Mark into that macro and keep it effective. Hunter's Mark only has a global cooldown, and sets off the GCD, so every time you hit that macro, it's going to cast hunter's mark and prevent your other shots from properly firing.
You can, however, add in Bestial Wrath into the /castrandom line, and it should work fine.
The reason for that is if you use /cast Bestial Wrath in the macro, it might get hung up on that cast until it can do it. /castrandom will only attempt to do it if it's available, meaning the cooldown is up.
If you absolutely want to have BW and HM cast at the same time, I just suggest putting them into a seperate macro together. I use:
/use Trinket (replace that with whatever 2 min CD trinket you have
/cast hunter's mark
/cast Bestial Wrath
/cast Rapid Fire
Sometimes, that macro has to be spammed a few times depending on latency and whether or not you are still Autoshooting... But it's a nice "WIN TEH DPS-CHART" button
REALLY IMPORTANT EDIT: Wow. While I was going into all that, it didn't even occur to me that you're a BM hunter using the 1:1.5 shot rotaion macro. look up the 1:1 BM macro, it's in the Pre-Raid Gearlist thread.
If you have points into Serpent's Swiftness you'll probably want something more like this:
#showtooltip Steady Shot
/cast !Auto shot
/cast [target=pettarget, exists] Kill command
/cast Steady shot
/castrandom Bestial Wrath
/script UIErrorsFrame:Clear()
that'll be better for your DPS and Mana, since it won't clip Autoshots.
Edited, Apr 12th 2008 3:32pm by ProjectMidnight