weird cacheing

suddenly older copy of my site is cached

[muszek]

I optimized my site a bit (removed session ID from links) in the begining of February (or maybe end of January) and noticed google indexing many of my pages right after that. Ranks up, neat.

I'm 100% sure I've seen mid-february version of my site cached by google. Actually, few versions, one every couple of days.

Came back from holiday yesterday and noticed that my ranks are back to the old, January positions... today I checked cached page and it's from January! Also, all those newly indexed pages are gone. Cached page was saved between Jan 23 and 27!

Can anyone explain that?

greetings,
mateusz mucha

one extra question... I keep seeing "You have mail: [ inbox:2 - unread:2 ]" every time I'm on webmasterworld... but when I click on it, there's Displayed 0 messages in inbox of 0 messages". Some kind of a bug?