increas text size in IE

This is kinda off post, but ive answered alot of questions here so maybe you'll let it slide.
When I go onto some sites and try to change the text height with the button on the IE bar, it wont change anything. Some it does (like the yahoo search page) and some it doesnt. Any clues how I can force it to work on these sites. The sites arent in panes or side (up/down) sub-windows (or what ever you call them), it's the main area of a page and many dont even have panes. I know i can just change my prop for IE to not use the site settings, but then I miss the neat color schems of some pages. I cant change the props per page cause IE props ar global so If I have 5 windows open and 2 cantankerous b*stards wont resize on the text and I change IE props, then the other 3 change too (they also reload which can suck sometimes).
Any Ideas or directions to site (I tried the main Win site for IE with no luck) would be appreciated.
I only posted this here cause you guys (or girls - dont wanna be politically incorrect now) seem to be good programers, as well as a number of good computer people that visit here.

P.S. No, ctrl-up/down or rolling the mouse doesnt work on these sites either. Forgot that one.
later.

p.s.s. I just noticed the text sizer for IE doesnt work with this forum page. Oh yea, I usually run with all my setting off. In IE props I have the sec lev at max and cookies to "No freakin Way, dude". The only thing I turn on in sec is download files and drag n drop/copy n paste. Most things are off in the Advanced tab as well (except some of the security stuff at the bottom.)
Yes, I AM paranoid, it's an old computer 800mhz p3, but it's my only one.

On WinXP SP2, IE 6.
Open "Internet Options", click "Accessibility...", under "Formatting" check
"Ignore font sizes specified on Web pages".
Then you'll be able to change font sizes on any page, but it doesn't effect the page colors.

Don't think there's any way to set it per page tho.

You might be better off trying a different browser, if that's an option.

As far as I remember, however, the "Ignore font sizes specified on Web pages" gives all text the same size – navigations, annotations, etc. – which can look rather strange and bad to read.
Yes, better use another browser like Mozilla/Firefox – it can scale font sizes proportionally even if the web designer specifies fixed font sizes (which is the cause for that behavior of IE).
A rather advanced approach would be to use a filtering proxy such as Proxomitron and write rules for the web pages to alter the size specifications directly...

yes, get opera(or the fox) and u can use the bookmarklets available to change fonts and do other stuff. also try ctrl and move mouse wheel to zoom.