Minecraft Server problem - imbis core ID error?

I have a multiplay minecraft server (small server just for me and a couple friends), took me a while to get it working - i've never run a server before, but i have it sorted now. Been playing on the technic launcher hexxit, volz and now trying to play tekkit, but it comes up with an error when i try to play on it - my single player works fine. I think it's a problem with the ID for imbis being the same as something else but i'm probably wrong. We've tried looking online for patches or fixes but couldnt find anything - if anyone has had this problem tell me please if you know how to fix it or if i should just go back and try a different mod pack, we've always wanted to play tekkit so it would be a shame:/ please help.

This is what appears when i try to play on my server

Forge Mod Loader has found ID mismatches
Complete Details are in the log file
ID 13782 from Mod ImbisCore is missing
ID 960 from Mod ImbisCore is missing
ID 1439 from Mod ImbisCore is missing

You can't connect to this server

Have you tried installing Idfix? Worked for me when I had item id conflicts. http://www.minecraftforum.net/...conflicts/

Also what Tekkit are you running? Tekkit, Tekkit Classic or Tekkit Lite? I highly recommend playing the newest one which is just Tekkit as the mods are more up to date than the other 2.