Yes, it looks like you are trying to run PAL (European) games on NTSC (North American) TV.
You can do what Spirantho said, but you may have problems if your TV does not support 50Hz scan and your screen will ROLL.
You can invest in Commodore 1084 Monitor and play the games using the RGB and Composite.
Some computer monitors/HDTVs support 50Hz 15KHz inputs on VGA, but you need 23pin>15pin converter. I have Dell SR2320L, works great with Amiga.
I have 50in LCD Sony Bravia (KDL-52w41000) and I know that 15khz does not work on it. Other model may support it.
Let us know what route you want to take.