In the "TOW the Thanksgiving Flashbacks" episode, Joey is in the Thansgiving 1992 segment. Yet according to the third season's "TOW the Flashback", Joey moved into Chandler's apartment in 1993!

I'm not surprised. I think it's been discussed before that there were a few times that the writers didn't get things straight with certain things on the show. Case in point, in the pilot, Rachel didn't know Chandler, but in TOW All the Thanksgivings(I think it was that episode), Rachel & Chandler first met at the Geller's back when Ross & Chandler were still in college.

Another thing I noticed, in the pilot, Ross tells Joey & Chandler that he hadn't had sex in a really long time, then in the 3rd or 4th episode, Carol tells Ross that she's pregnant. If he hadn't had sex in a long time, how did she get pregnant?

I have noticed some goofs through out. For example in the Beging Rachel talks about how she is doing her own laundry and then in the next episode she learns how to do Laundry. Another mistake occurs when Ross tells Rachel who he's been with and he leaves out Julie. There are probably more but I can't remember them now.