I tried making the resolution the same no difference. What's happening is the letter actually looks good when I put it in as a png or jpeg, but as soon as I use the pan/crop to have it fill the screen and then scroll the view from the top to the bottom, it then looks like it has an interlacing issue. I turn on the reduce interlace flicker switch and it helps but still looks bad.

When I try to copy the text and past it I only get one line of text.

I guess my option to get it done is to shoot it. It's just getting a smooth consistent rate of shot from top to bottom is tricky.

Try making your jpeg as wide as the frame width, but as long as it needs to be to hold the desired text. Import the file to the timeline. When you go to Pan/Crop, adjust the width and height to your frame size. Expand the Source section of Pan/Crop and set Maintain Aspect Ratio to Yes and Stretch to fill Frame to No. Now you can position the cropped frame at the top and use keyframing to scroll through the text.

I've tried to do this numerous times and have given up on it as typewritten material (especially a full page of closely spaced text) does not look good on a TV screen.
I started doing what I see TV stations do all the time in the same situation and that is to have a blurry copy of the letter in the background with electronic text (either still or rolling) in the foreground.
Forget about using the Credit Roll feature in Vegas as it's a joke and try the following method which works like a charm :)
Place a text media event on the timeline.
Set it to the length you want, set the text size to 20 (this is just a starting point so feel free to adjust it later as needed).
Copy and paste all your text into the one screen.
Switch to the Placement tab.
Adjust the Y value to a positive value high enough that the text just disappears off the bottom of the screen.
This will automatically create a keyframe at the beginning.
At the bottom of this timeline, hit the Last Keyframe button and change the Y value to a negative number.
i.e. if the beginning was +4, the end is -4.
Adjust your text size, font colours, border, drop shadow, etc. as desired.
Close the window and play it.
That's all there is to it.
hint: if this is for an SD project, make the text event properties twice the resolution of your project (i.1. if it's NTSC 720x480, make your text 122x960) as this will help it look cleaner.

Mike