I think he has it, but I don't know ...............................

Maybe he just wants his son back, how do we know what the sickness even is yet.

how would you react if your child was abducted? Just shrug it off and carry on, give the guy a break, he's a concerned father.

You know, it may just be wishful thinking because I like the character, but I've been thinking maybe he was lured away for his own protection. If he was hallucinating the conversation with Walt, then yeah, I think he probably has the sickness. OTOH, if there really is some kind of "connection" to that computer then I think Walt would have tried to get him out of harm's way. I sense something really bad is about to happen in camp and that the Others know what it is. If they have shared that with Walt, as in told him that they took him to keep him from harm, wouldn't he want his Dad out of there too? Probably just wishful thinking, but there it is....:smile:

yes . . . he must be sick . . . or maybe just deluded by grief

I really like your theory shootfire! It sounds plausible and exciting... let's see
I personally don't think he's sick either. he seems to be really upset about walt, and determined to find him.. he tried it before in the beginning of season 2, and now that he's heard from walt (supposedly) he's doing it again..
OTOH, in 23rd Psalm when jack had that conversation with michael and stood up to look at the screen, it was blank.and to my knowledge, they didn't show michael pressing a key or anything to erase his exchange with walt. that might mean he imagined it all and if so, then he may really be sick...
as always, there are a number of possibilities which is why i love Lost!