It is a message that your system had a "bad" shutdown, [could be almost anything not normal, not necessarily BAD]. Many mobos will automatically drop the memory bus / FSB to the lowest possible as a protective move. If the problem was just a single goofed shutdown, go into the BIOS and reset the memory bus to 333/166, whichever your BIOS calls it [or the FSB to 333]. It is stated differently in various BIOSes.
If you actually have DDR333 and it won't run at 333, possibly your BIOS has a Manual mode for setting the memory speed. If it does you can increase the Memory bus speed in one MHz increments. Work the manual setting a little at a time until you find the highest stable setting.
I had an ASUS mobo that wouldn't run PC133 at 133, but I could run it at 129 MHz.
One other thing, if you have spread spectrum enabled in the BIOS, disable it. that can give flaky memory a problem. In the ASUS, with spread spectrum enabled, best I could do was 118 MHz.