To get Castlevania Chronicles to work, keep pressing F4 and F5 or F5 and then F4 and be patient. It won't seem like it is going to work, but it will. This is the way I had to do it and I got the game (US NTSC version) to run.
For Castlevania SOTN, what worked for me was to set the country dection to Force PAL mode and then run the game. It got past the memcard screen and gave me a new game. I played for a bit and then saved at the first save point I found. Later after I had exited and returned to to play some more, I set detection to auto detect and it loaded up just fine. My version is the US NTSC version. Hope this helps.