Yeah, I'm guessing that what's happening is that both the Focus gain number and the intelligence are being repeatedly incremented once per encounter. The intelligence appears to cap out at 35 (at least, my Cipher isn't gaining any more than that), but I suspect that there wasn't a hard ceiling on what your focus gain could be, so the numerical field that stores the value is probably wrapping around or something and breaking things. If that's actually the case, then wearing it longer should theoretically make your Focus Gain return to normal values, but the Intelligence is still borked.
I have an idea of how to test this theory. When I get a chance, I'll perform the following test with a character whose intelligence is less than 35:
1). Record the intelligence value of the Cipher/Wizard/etc... before placing the Talisman on him/her.
2). Place the Talisman on the character
3). Enter combat
4). After combat, take off the Talisman
5). Record the intelligence value of the character afterwards. Is the value 2 higher than in step 1?
Mine peaked at 42..but it doesn't seem to actually give the AoE bonus, just the will bonus.
