Well, you certainly grabbed that detail from the depths... I'd actually not put two and two together here and come up with that one.
You're correct of course and RM is written in VB6. I was told that a good while back by a chap in the know but whom isn't on these forums. Anyway, that's a totally useless fact but never mind.
I actually can't remember when I last used the expression twipsperpixelX and Y... my brain isn't allowing me to access data much beyond a few weeks or months so I've no chance with that lol.
Seriously, it was only during a course I touched on those things as they were soon to be old hat and I definitely cannot remember which course... I did so many back in the day. But your argument is persuasive and could well be the likely source for the 'errors'.
Web design is great when done with decent CSS and heights and widths of sites are done in percentages. I don't often used fixed width or height unless absolutely crucial to the design and the client's wishes are considered too.
There is so much flexibility using these dimensions in that way where columns for example can be a real pain when using fixed dimensions. Percentages allow themselves to be utilised for tablet/mobile and large screen displays as you know but I sometimes try and use a piece of code that reads the screen size of the user to give best results. Although even that doesn't work all the time because browser code is altered and removed on each update... happy days.