I've been flying EBBREGKK via a reloaded flight file. Yesterday TO was marred by the plane not complying with FMC Speed (massive underspeeding to stall buffet) until Cutback Restore at 3000 (though AT, LNAV, VNAV and CMD A were all on OK). Based on another post, I tried fully loading the non-winglet -800 first, then reloading the -800 WL as desired. This time, TO was fine, FMC Speed was well tracked ... but suddenly, above 3000', the entire FMC active flight plan disappeared from the screen and I couldn't find any Coroutes either ... Anyone else had this? A bit disheartening when the bird is soooo beautiful .... Apologies if a redundant question. Tried to check other posts, but couldn't see whether this was already a reported issue that would be resolved in SP1 or otherwise. Thanks! Davld