Yeah, this is one of those little irritations that plague so many critical yet overlooked components of modern living. You can't just put any strainer in any sink. They only sort of work. If you lose, break, or wear out the original, you probably have to buy a whole new drain assembly to get it to work right again.

Do you use the stopper? I don't every fill my sink up so I have been use a fine mesh sink sieve like the one below. Works just fine for my style of cleaning.

Here is a link that might be useful: Sink Sieve