Speedlight radio trigger problems?

I bought 3 Cactus V5s recently to go along with my Nikon SB-600 and SB-700.

I'm shooting a wedding soon, and here's my setup plan for the reception- I'm going to have my SB-600 on a light stand with a V5 on one of the corners of the dance floor… Then I'm going to have a V5 on my Nikon d300s and my SB-700 on top of that with a lightsphere.

Here's the problems I'm experiencing:

1: Sometimes both of the speedlights won't fire. If I press the button on the V5 they both will fire, but not when pressing the shutter release button. If I remove the V5 from my camera and reattach it usually that's an immediate fix.

2: Also, sometimes my SB-600 will fire, when pressing either the shutter release, or the V5 button, but my SB-700 won't. It seems like turning both speedlights off, and turning them back on starting with the SB-700 fixes that.

These are really annoying issues. The reason I bought radio triggers was so that I didn't have to deal with flashes not firing. Does anybody know the cause of this and how it can be prevented?

I would use the SB700 in the Commander Mode on the camera and the SB600 as the remote flash.

On the other hand, if you are using one of the V5's as the trigger from your cameras hot shoe and using the other receivers to trigger the other flash units, you may have to contact Cactus for technical assistance if they are not working as advertised.

I use either Pocket Wizards or Profoto Air flash triggers, so I have no direct experience using other systems.

See what Cactus says.

The Cactus triggers are notorious for being hit or miss. I would never trust something as important as a wedding on a set. The standard radio trigger used to be Pocket Wizards, but they were found to be unreliable when they released the TTL series. Check Craigslist or eBay for some Pocketwizard Plus IIs or Plus IIIs. They have no TTL foolery and are rock solid reliable. There's cheaper out there, but if you're serious about shooting a wedding get serious about your gear.

Two possible answers. It sounds as if the bottom hotshoe contacts on the V5 are not making proper contact or lining up correctly with the sync contacts on your cameras hotshoe, read your manual the number of times I've seen people use radio triggers the wrong way round on the hotshoe then wonder why they have a problem. Operating the switch on the V5 closes these contacts and the unit works, the switch on the V5 shorts out these same hotshoe contacts so the units are working.

Alternatively Nikon flashes go to 'sleep' readily, like after 5 seconds, it's a real pain, they need it because they are prone to overheating. The Yongnuo radio syncs keep sending a signal every few seconds that keeps the flash awake in their Nikon versions. Nikon flashes are well known for needing a 'wake up' signal before the sync signal. Try triggering your camera twice in rapid succession and see what happens. It could be that your SB-700 is going to sleep before the SB-600 which answers your other dilemma.