evolution stalls & freezes all of a sudden

i have ubuntu 10.04 LTS with evolution installed since a couple of months.
very happy with ubuntu, and untill recently with evolution too.
since yesterday however, after those first months without any issue at all, evolution behaves strangely.
i have version 2.28 installed since a couple of months, with a gmail account, and though it worked perfectly before, since yesterday it takes ages to send and receive, showing errors while "storing folder 'inbox'" or 'retrieving message 1763' etc.
and it keeps on having a slow and hard time untill it just freezes and i'm forced to force quit.
anybody any idea as to what this problem all of a sudden might be?
thx, d.