Oh right - ok. In that case, I'll try to track down an excellent article which provides good evidence NOT to use built-in cursor updates but to do it manually instead...
Edit: Here it is.
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden