Perhaps it amusing for someone or serves as a warning..
I had active reservation to Helsinki Hilton Strand for this weekend and according to fare rules it was possible to cancel up to 2 days prior arrival.
I started to cancel my reservation in the late hours (around 11PM) of 13th of December and hhonors.com did not let me do that (official reason: deadline expired).
So I called to Helsinki Strand and helpful gentlemen told me that it must be canceled 48 hrs before arrival - not 2 days (deadline was according to him 6 PM on 13th of December). Live and learn
After some friendly arguing he canceled my reservation and issued a cancellation number. He also confirmed that no additional charges would be made.
I thanked him and logged to hhonors.com, where my original reservation appeared as a "late cancel". There was also new and very much active reservation to same hotel for same dates.
I called to Hilton reservations in US and heard that I would be charged for one night, as cancellation was made too late. I also heard that hotel had made me new reservation for the dates I wanted to cancel.
Called back to hotel. Friendly gentlemen told me that there are no reservations whatsoever and "no one in hotel is expecting me" (which does not sound so friendly after all , but perhaps it was a language barrier)."
No it was around 1 AM on the 14th of December and I went to sleep.
I woke up, logged into hhonors.com and found out that now I have TWO active reservations for same dates and into same hotel (second reservation was also made by Hilton Strand). On the edge of panic I called to Hilton customer service center here in Tallinn and finally they sorted it out how to get all three reservations canceled; I also got confirmation in writing from hotel, that they would not charge me for late cancellation of those reservations - which I appreciate very much. But itīs still quite interesting how I wanted to cancel one reservation on time (it was 2 d a y s prior ), and ended up with three reservations - all of them "late cancellations" according to hhonors.com

In order to save my nerves I am not going to make any more phone calls. And I will check my credit card statement very carefully next month

Cancelled
LateCancel Hilton Helsinki Strand 12/15/2006 -
12/16/2006

Cancelled
LateCancel Hilton Helsinki Strand 12/15/2006 -
12/16/2006

Cancelled
LateCancel Hilton Helsinki Strand 12/15/2006 -
12/16/2006

PS: I am not accusing anyone or complaining. All ended well, but whole ordeal was quite funny - at least for me.