jit.cellblock weirdness

This is an intermittent problem that I've been ignoring for a while, but I can't ignore it anymore because my client wants it fixed. From time to time (ie rarely, without predictability) jit.cellblock draws the columns in the wrong order, most recently the second column is drawn last (ie the first column that's not the header column). The cellblock is referencing a coll, and the data is in the correct order in the coll, and when its changed in in-place editing mode in the offending column, it appears in its correct place in the coll.
So it seems like a draw to screen issue-- the data contained by the cellblock is not corrupted in any way. Even the column widths, colours etc are correct, just drawn in the wrong location.

Has anyone had a problem like this? Please respond if you've got any idea about what I'm on about, or if you've had a problem of a similar ilk. I can post the cellblock if anyone wants to see it.
T