Shameless commercial plug... 
For hardware modders living in the NL, if you're considering a V9938 -> V9958 upgrade (now or some time in the future), you might want to know that Dick Best (www.dickbest.nl) have turned pin version of the IC sockets you might want to use, in their webshop.
Reason I'm letting you know is that very few electronics shops have these shrink DIP sockets, and the turned pin variety is even harder to find. Not to get into a turned pin vs. low-cost discussion here (or whether you need it), bottom line: the turned pin variety is more expensive, but overall better quality.
Sometimes you see 64p turned pin DIL sockets advertised, but usually these have standard 2,54 mm pitch, read: V9938 or V9958 won't fit in there. And even with the correct pitch, there exist IC sockets with different distance between the pin rows. I've ordered a couple of those IC sockets from Dick Best, received them today, and can personally confirm they're the correct dimensions for an MSX2/2+ videochip.
Of course the cheapest & most reliable way to place a V9958 is to solder it directly into the board, but then any next replacement is same amount of work as the 1st time... :P
