hmmm maybe try to flash other modem, i have LP6 and no problem for me.
here is cwm flashable lp6 modem, try to flash it , im using it and for me no problems even wifi/3g download/ upload speed is faster then the stock modem of this rom
http://www.mediafire.com/?r79953xg2s1aama lp6 modem
i really don't understand why this is happening, tried modem LP6 but it did not solve the issue, knowing i did not have this issue with gb roms or ics stunner , imilka roms
i had a french note, flashed a kk2 rom via odin pc,
rooted it with cf k1 kernel using initial cf root flasher,
then i flashed cf repack ics through mobile odin
with wipe cache data marked.
then i entered cwm and wipe data/factory reset, wipe cache, wipe dalvik cache then i flashed criskelov2.
i don't know why on every bluetooth headset i hear gaps only when wifi is on