I've had posts deleted from multiple sections, many times over.  OP, this is just how the forum is, so get used to it--and if the post that got deleted was just you thanking another member for his post, what's the big deal anyway?

Also, in the future if your post count happens to drop and you get no notification that a mod deleted your post, it means that a thread you posted in got deleted.  That happens and makes people wonder who deleted one or more of their posts. 

I wouldn't say bitcointalk is a tightly-run ship, but some sections are more heavily moderated than others, and the tech section might be one of them.  And to echo all the other members here:  learn to quote posts properly so as not to annoy everyone.  Only quote the particular part of a post you're responding to.