XIRR: a bug?

[gummy]

Excel's XIRR function has the following format:
=XIRR(cash flows, dates, guess)

Somebuddy sent me the following problem:
http://www.gummy-stuff.org/xirr-problem.gif
The XIRR return says 0.0% ... which ain't right.
Now change the initial $200 investment to $200.01 (or even $200.00001) and the correct XIRR appears.
Mamma mia!

Does anybuddy here get the same curious behaviour
... or is it my ancient version of Excel?

P.S. Change the guess to something negative and you also get the correct XIRR.

[oldchippy]

Try formatting the cell to number and increase the number of decimal places

[gummy]

Alas, that don't work either.

The "correct" XIRR value is -4.81% which I can readily get uses Newton's method:
http://www.gummy-stuff.org/xirr-problem-newton.gif