Yeah, as said, that's normal.
You have a few options.
If you want to use a computer monitor, you'll need a scan doubler.
Indivision AGA MK2, when it's re-released, is the top of the line.
There is another one being released soon (not sure when) also, the Scan Juggler.
If you're handy (even marginally) with a soldering iron, you can pick up a GBS82x0 on e-bay for $30 ish (and then less than $10 for a DB23 plug) and use that. It's not as nice as some of the other scan doublers, but the price isn't bad. ;-)
And then there's various old scan doublers that show up on e-bay not too often.
Or, if you can find yourself an Amiga monitor (1084s, NEC Multisync 3D (there were a few other models, but not all NEC multisyncs will work), phillips made an Amiga monitor...) that will work with PAL or NTSC.
Good luck
desiv
