Googlebot question

[pc doctor]

Last night I made some changes to my site. I had only a page ranking of 1 with google at the time. My page was showing up on the 3rd page of search results for the keywords I was using to test the site with google.
Just now I checked it on google and my page rank is 0 and it's nowhere for the same keywords.
I checked my log and found this

Googlebot 15 21 KB 29 Apr 2008 - 20:00 .thats showing that google hit my site at 6pm today. Do I assume that the changes I made to my site were looked at in a negative way by google and I should sit down and make more changes or make things back like they were before I made the changes.
I want to know if I am looking at this correctly and if it's necessary for me to react so fast or even if this google bot hit would make such a fast change. I also made changes last week but nothing changed at all. Could the negative change be from the changes I made last week or the ones I made from last night.

[Horus_Kol]

not knowing what content you did have and do have on the page in question, it is really quite impossible to know what GoogleBot's reaction to those changes would be...

[pc doctor]

I think what I would like to know is would the googlebot make changes to my ranking that fast with a minimal change. I played with my keywords adding a couple and changed positions of a couple. I added some text that used more of my keywords at the upper end of my page. That's really all the changes I made. Nothing major. So content aside I want to know if some fairly small changes would make that big of a difference that fast.
When doing changes like this would a single googlebot crawl make page rank changes right then or does it have to be a series of crawls to see the changes.

[Horus_Kol]

it would see the content changes immediately, i would say... but I wouldn't leap to the conclusion that your pagerank is suffering just because of that...

[seo4china]

It's impossible to assume Google SERPs or PR behaviors just from a single Googlebot visit...

[Lyndsay]

Did you check with your Google webmaster tool, you can see when Google visited last your site.