It will be choppy for the first few seconds. This is actually quite normal. But it should smooth out after that.
Also, it won't be 100% smooth as you're not syncing with the display, but an internal logic rate instead. During an actual game, this little jitter won't really be noticed because you'll be concentrating on the game rather than how smooth it looks (or at least the player will). You're specifically looking at how smooth it is, so you will notice it's not perfect.
It looks smooth when you comment out the While..Wend lines because you're then syncing with the display hz of the monitor. By doing so, you've taken out the timing code so it will now run at different speeds on different systems/display settings.
Also, it won't be 100% smooth as you're not syncing with the display, but an internal logic rate instead. During an actual game, this little jitter won't really be noticed because you'll be concentrating on the game rather than how smooth it looks (or at least the player will). You're specifically looking at how smooth it is, so you will notice it's not perfect.
It looks smooth when you comment out the While..Wend lines because you're then syncing with the display hz of the monitor. By doing so, you've taken out the timing code so it will now run at different speeds on different systems/display settings.