We've been testing the propeller's speed while running our telemetry units as well as a variety of graphic video drivers and we've found that using a 14.31818Mhz Crystal ($0.55 at digikey) will reliably clock the Propeller at 114,54544 Mhz with a pllx8 ... The test was conducted at different temperatures for the past 48 hours.
Now that you have this information, go and get a 14.31818Mhz Xtal (or rescue it from surplus PCBs) and start developing a better, cooler, video driver
P.S. both the loaded (18pf caps) and the unloaded crystal worked fine - although I personally prefer the 18pf loaded crystal
The beginning of your demos (like graphics.spin etc) will need to be altered as follows:
_clkmode = xtal1 + pll8x
_xinfreq = 14_318_180