When trying to update (creation works well) a post, which has attachements it often (nearly) happens that my mysql 5.0.18 crashes.
I looked into the statement and saw that it shouldn't be (around line 568):
( a.attachmentType =3 AND thumbparent.IDTHUMB = a.ID_ATTACH ) ```
mysql 5 doesn't crash when using this instead:( thumbparent.IDTHUMB = a.ID_ATTACH AND a.attachmentType =3 ) ```
Basicly this seems to be an mysql 5.0 issue, but this quickfix helped me to keep my site working with smf attachements.
I posted already a
bugreport on official simplemachines site.