custom fields: customer text input plugin, price-per-letter --bug?

[ArtRight]

Hello!  J2.5.3, VM2.
I am having 2 issues using the custom fields "customer text input" plugin with price-per-letter.  http://www.artright.biz/our-online-shop/another-type-of-frames/word-mats/custom-word-letter-mat-for-3-x5-photos-detail.html

1--If you add more than one of this product to the cart, they are all added at the price of the first one, regardless of the number of letters.  It does the math correctly on the product detail page, but adds the product to the cart at the same price as the first.
2--In the admin backend, I've set the "Size of input" to 18.  However... a customer can enter as many numbers as they like!  The plugin does the math correctly... but we are not able to make the product with more than 18 letters.

I have searched the forums, and tried this with the "Beez2" and "Beez5" templates.

Thanks in advance for any assistance.  I hope that I can get this working!

[ArtRight]

And, if you delete the first item(s) in the shopping cart, the price of the remaining one is automatically corrected.