Thanks to the comments from Jeff Usher, it appears my initial thoughts about the CRA prescribed rates were incorrect. I consider myself well-researched in these matters, but once in awhile, things slip and this was one of them. Thank you Jeff.
The CRA, on June 28, 2010, published the third quarter prescribed rates.
Apparently the reason for the delay is that Bill C-9 implemented a reduced rate of accrued interest for corporate overpayment of tax. Corporations were using the CRA as a savings account, where they were getting higher rates of interest than the banks. In the previous quarter, this amount was 3%, but going forward it will be 1%.