Church Times cries "manipulation"

No they're not saying it about the Chief Rabbi's willful misrepresentation of the General Synod resolution to disinvest from Caterpillar. The claim is made about their poll about whether or not the C of E should disinvest. Here's what they say:

On 17/02/2006 we asked you "Should the Church disinvest from Caterpillar? (We are aware that voting on this question is being manipulated and no conclusions can safely be drawn - editor)"

Here's the latest result:

The results were:

Yes: 6923(63%)
No: 4077(37%)

Total: 11000

Here's the result when I posted on this earlier:

The results were:

Yes: 3166(65%)
No: 1687(35%)

Total: 4853

Now I think they should say what the manipulation consists of. Is it people simply voting many times from the same pc? If so they could at least tell us whether it's the yes votes or the no votes that are doing this the most. I should point out though, that since the "manipulation" was discovered, the no vote has risen (slightly) relative to the yes vote.