AMD Phenom B2 core has speed problems in the third core

While most reports claim that the reason for the release of the B3 K10 core is the problem known as the L3 TLB bug, some more information has surfaced which indicates that they are also experiencing some problems with clock scaling of the 3rd core. This explains why AMD is so interested to release the triple core processor known as the Phenom X3, as some people are disabling or underclocking the third core, in order to have a stable machine. Add that to the fact that they aren't waiting for the B3 core to release the Phenom X3.
Some people are experiencing problems with overclocking of the third core while others have to underclock it, to about 2GHz, in order to maintain stability - which they can't at stock speeds. The strange coincidence is that most, if not all, of the complaints are of the 3rd core.

This is a problem as important as the TLB bug, that may explain why AMD hasn't released processors faster than 2.3GHz, while it is able to send some 2.6GHz samples to reviewers. While significant data is not available on the TLB bug subject, it should be present at all speeds and not just higher speed grades. After all, they are enabling the TLB errata for all B2 cores.
Keywords: AMD Phenom X4 3rd third core problems
Forum threads where you can read about this problem are hosted here and here.