Belboz, they list what is supported at the time of release. Such was the case with early revisions of the nForce2 mobos that listed 333fsb support but not 400. Many of them just needed a BIOS update, but at the time, 333 was the official standard and what was available in processors. Listing a higher spec would mean they would have to honor the RMA requests of overclockers and/or troubleshoot, as already mentioned.
Using your example, you're talking about a mobo released in 2002 (NV7-133R). There was no such thing as a Mobile 2400+ back then, so listing anything above 266 would have meant officially supporting overclockering at the time.
I guess your right. It's just funny when you buy a board that says it has a 266mhz DDR FSB max, then you open up the BIOS and find that it goes up to 320mhz.
It seems that FSBs are one of the few exexptions to the marketing rule, which is state the highest possible speed, and cheat/lie if necessary.
Take that last post on hard drives for example. They say it's an 80gb hard drive, but once you go into windows you find that there is only 74.5gb.
Would be kind of stupid if it were the other way around, and you bought an 80gb hard drive and found there was actually 85.5gb.
I guess I'm just so used to seeing all the marketing tricks that make people think they're getting more than they actually are, that it bothers me when they say your getting less than you actually are.