In researcher GUI sometimes when i swapping items between slots(not by shift) i get this crash:
http://pastebin.com/2G56zPsR

this is odd and shoult not happening... This means this researches is owner by nobody... does this happens always ore only sometimes ?

only sometimes.

I think this could be related to some of the core mods from any mod, I think I can fix it but it is still weird it happens if you swap items.

yes.

Could you try this version ?

Looks like the crash disappeared, but i spot this on server so if it appears again i will tell you.

I installed this version to my server, and after some time i again got similar error:
http://pastebin.com/LnqwnDrU
My server is vanila Forge

Hmm, try this version, if this doesnt crash ater about 30minits can you please give me your log (from the client)

I think the crash is fixed, but there is still some errors when i swap items.
Log as you asked(Contains only those errors): http://pastebin.com/8i8AAh2V