Rollover budgets for January 09 have screwed-up limits

Let's take an example:

My budget for Books begins in November 08. It has a limit of $50 per month, and is supposed to roll over any extra.
In November I spent $23.58 of a limit of $50, leaving $26.42 to roll over.
In December I spent $34.83 of a limit of $50 + $26.42 = $76.42, leaving $41.59 to roll over.
In January so far I have spent $0, which means my limit should be $41.59 + $50 = $91.59.

But Buxfer says my limit is $126.42. My other rollover budgets are similarly broken with weirdly high limits in January. The non-rollover budgets are fine.

(Secondary issue: in December, I actually spent $34.83 and received $10.55 in refunds from a book I returned. It's all tagged under Books -- shouldn't the Books budget actually think I spent only $24.28 in December?)