Subtle lag on xbox live ( worse than on ps3! )

I used to play A LOT of ssf4 on the ps3 psn. Then the outage came and not wanting to wait a month to play online I bought an xbox. Everything was working fine, and I did get into online matches quicker than in the ps3, plus there were more players … and all that time I was playing endless matches not worrying about my pps ( I got 15k, 20k on the ps3 so why bother ).
These last couple of weeks I wanted to play some ranked matches coz of the new point system for the arcade edition and also to find quick matches for the new characters, and now it seems I have problems when playing online. I noticed that in some matches, I just wasnt blocking at all during random intervals, or not completing a combo that I know 200% how to do it. This happened rarely. At first I thought my reactions were slow that particular day, but then I realized it wasnt me but my stick wasnt responding at times. I exited online mode and tried some moves on training mode. My stick worked flawlessly. I then thought the culprit was lag, and maybe my internet was having a bad connection at certain times, so I tried playing at different times of the day, me hosting or myself playing with someone else as host. Same thing. The round starts normally and suddenly I wont be able to hold back and then I got owned by a stupid noob combo.
At least in the ps3 when I got a bad connection, you could feel the lag easily … but here is so subtle that sometimes you think you just suck coz u dont realize its the lag messing up your execution.
Somebody else experienced this? Does the upgrade to arcade edition has anything to do with it?
I remember I didnt have problems at all in the regular ssf4.