Excess DIRT deducted by banks? Who has it?

Hi all,
while filling out my tax return for 2009 I came to the point where I had to enter Deposit Interest earned and DIRT deducted. I groaned when I saw that there was a rate change from 23% to 25% beginning 7/4/2009 and Revenue want me to fill in seperate details for the 1st 3 months and remaining 9 months, for interest earned and DIRT deducted. I groaned because I knew the banks' certificates only gave a single figure for the full year!
Then I did a quick calculation based on the certs issued by the banks to see what rate they deducted DIRT. Lo and behold; Anglo, Northern Rock and PTSB all deducted DIRT at 25% for the full year; Rabo deducted 24.41%.
This leads me to believe that Rabo correctly deducted 23% for the 1st 3 months and 25% thereafter, but the other banks over-deducted 2% for the first three months!!
This begs the question, if this is true, what have the banks who over-deducted, done with the extra 2%? Have they handed it over to Revenue or have they kept it for themselves?
It's only €10-€15, or so, all told, in my case, but it's MY €10-€15! and if there is €80 billion on deposit in Irish banks (as I think I've heard said on the radio), the excessive deduction could add up to €10 million or more?

I'm tempted to highlight this to Shane Ross! Or have I jumped to the wrong conclusion here?

regards
Ricta

Not 100% sure but if the interest was paid annually in December I would say the 25% rate applies. Monthly interest payments would incur 23% on the first three months and 25% on the balance. Just a guess though

The DIRT rate depends on the date the interest was paid to you, not the period in which interest was earned.
Perhaps Rabo did pay you interest in the early part of the year?

I guess so

I guess that would explain it. Ah well, no email to Shane Ross so.