Just to update,
I had not experienced the issue again after refitting the lens..
Crossing my fingers thou that it doesn't surface again.
So far i have no issues with my Mem card thou' i have not crossed 100 shots per time yet. I always format my mem card when i re-insert in the card after uploading into my pc. Not sure if there's any link but its just something i read from Kenrockwell's website.