can you tell the revision? as there are 3 X2 4000+ CPU's made by amd, 2 of them were on 65W and 1 on 89W thermal design.
write the revision and L2 cache. however, in both cases, no matter what revisin you have, 55 is safe, though HIGH, voltage should be b/w 1.20 - 1.35 (depending on the CPU revision)
This is true, when it comes to voltages you can actually change and set yourself, one should only care what they set in the CMOS Setup, and what the CMOS reading's are outputing.
IN windows software is terrible for voltage reading's.