If your sound card has a real ASIO driver, that's the best thing to use. If ASIO is messed up, try uninstalling, rebooting, and reinstalling your audio driver. Changing the buffering setting could help. If you have trouble with the Play from RAM setting, you can disable it safely (MC is bitperfect either way), and you might want to
test your ram with MemTest86+.
Playing from RAM with high-resolution stuff might just be difficult to use on XP though, which is going to be limited in RAM to less than 4GB (unless you are using the 64-bit version of XP, which is flaky all on its own).
If you are using ASIO4All, then you should remove it and just use MC's Kernel Streaming mode because ASIO4All is just Kernel Streaming itself wrapped in an ASIO "shell". No need to use the shell (which could be flaky) when MC can do it directly.
Lastly, Windows 7 is much better. If your box can run it, get it.