There is no problem and no fix needed.
DDR stands for
"double data rate", which means that the effective memory bus speed is
doubled through some signaling trickery, understanding of which we can safely leave to engineers.
That being the case, a good fight could be had about which frequency should be referred to when discussing the bus speed of such memory -- the true frequency or the doubled frequency. Marketers, of course, like the larger of the two numbers, so the doubled one is more commonly used. Others, including makers of Everest, insist on reporting the actual (not doubled) number.
As you probably realize by now, 166MHz is exactly half of the 333MHz you expect, and it is the normal clock for your RAM in terms of the true frequency it runs at.
As a side note on that subject, Pentium 4 front-side bus is quad pumped, so all those shiny new "1066MHz FSB" Core 2 Duos are actually running the front-side bus at the much more realistic 266MHz.