Sorry for the double-post, but I've just discovered that Technician DOES work on Hidden Power!
The test subjects:
- one L84 Technician Ambipom with 23\11\23\5\0\20 IVs (HP Bug 33), with a Special Attack of 110
- one L78 Celebi with a Special Defense of 181
The null hypothesis: Technician does not work on Hidden Power. Therefore, it will have a damage range of 54-64 (according to Netbattle's damage calc)
The alternative hypothesis: Technician DOES work on Hidden Power, therefore it will have a damage range of 78-92.
So I went into a double battle and had Ambipom attack Celebi with HP Bug 33. First time it did 92 damage, second time it did 88. So Hidden Power clearly got the Technician boost here.
One really odd thing I noticed - early on I tested it with L81 Ambipom, but HP Bug 33 only dealt 72 damage to Celebi, which was slightly below the damage range it listed for the Technician boost (74-88). So I had to use a few Rare Candies to level it up a bit and double check to make sure I had gotten all the IVs right. So I can think of two things that might be responsible for this:
- The Hidden Power calculator in my stat calc is slightly wrong. Netbattle actually lists the Hidden Power for the same IVs as HP Bug 34. However, Netbattle cannot be right either, because the 72 damage still falls outside the damage range.
- The damage calc for Netbattle is slightly wrong. I looked at several ways to approximate the damage. The most accurate result, methinks, is when I plug in 49 for the move power (33 * 1.5, rounded down), getting a damage range of 73-86. But I also tried checking off STAB, the weather boost, and setting the battle mod to -1 (not all at once, of course).
Despite the odd discrepencies, it's pretty clear evidence that Technician does boost Hidden Power.