Hi, if I'm attaching a redstone energy conduit to the power tap the reactor control GUI freezes and it only refreshes once if I re-open it. If I attach an energy cell, I can see the numbers in realtime, but if I connect even one redstone energy conduit to that cell, the control panel freezes again. I have to break the reactor and put it back again to reset.
Using version 0.3.4A2 with Tekkit.
Any idea what could cause that?

With BR 0.4 approaching stability, I'm cutting off support for 1.6.4 and BR 0.3. Sorry.

Understandable. Switching to 1.7.10.

This is the tekkit mod list.
http://www.technicpack.net/tekkit#mod-list

I think my world got corrupted as it does weird things. Crashed a few times when I used multimeter on conduits after relocating them it showed Null instead of saturation, had to relocate that part again and now it's working, however the GUI is still frozen, but it provides electricity. I'll try to reproduce it with TE+BR only later.

This sounds like a networking issue, but I'm not able to reproduce it myself. Very strange.

Does this happen in a world containing only TE and BR for you?

I've been having this issue for months now. Not sure if it corresponds with Thermal Expansion Conduits, but it does happen with passive reactors and also turbines. The strange thing is, the GUI will also unfreeze again after a while (and re-freeze). I have not systematically tested it, but I think it occurred with either Thermal Expansion Conduits, Energy Cells or Tesseracts attached to the Power Tap.
Running Tekkit here, which is on 0.3.3A still.

You can also post this issue on the tekkit tracker. I remember one user posting similar issue on multiplayer after the client was running for several hours. He will answer you in minutes :)
Find your forge chunkloading settings. I remember BigReactors needs a change there. Look it up.