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Oh I thought it was just me..I was wondering why I was getting so many repeat comments after upgrading to 2.65

There wasn't anything in 2.65 that would specifically cause repeat comments.

this is bad ... I upgrade MT to 2.66 and there is this 2.661 released just in 24 hrs..

Bad? I thinks its good that they actually release fixes quickly.

It would be nice when such things happen if a patch file was released with just the affected files. It would save time and bandwidth to upload just the changed files for those of us that already had 2.66 and just needed the fixes.

(I already got the four changed files in another thread, just adding this as a suggestion)

Thats not such a bad idea. I too saved much time and effort only switching those files.

In the annoucement they mention closing old comments-- how does one do that, without it hiding the comemnts that were made? And since I've got years and years of posts, do I have to do it by hand?

Run this script. It makes the whole process of closing mass comments simple.