This has happened to me twice in the last ten days playing at my local casino. The other day I had 75C and the board came 6c4c10c, not only do I have a made flush but I've got the straight flush draw. I didn't slow play, firing out 20 dollars, then getting raised to 60, I then shove. The guy thinks for five seconds and then calls with K2C and I miss my draw.
The other time I hit a diamond flush on the flop too, I was holding 89D and someone else had a J6D to beat me. So it seems like here lately it's happened quite often. And you lose your stack everytime, it's very hard to avoid losing your stack when flopping a flush.