So I used dialup (before you flame... I have a reason!) but I digress. I noticed something interesting. My website I am targetting a particular keyword. When I login my site will show up #3 in google. If i logout of dialup and reconnect and check it again, it will show #7, or sometimes page 2, it never stays in the same place everytime i reconnect. Whats up with that?! It's so bizare!
Google SERPs makes use of geographical and interest-based order So, if you e.g. visit your site more often (or google can see that you're logged into your account and knows that it's one of your sites), it will be shown at higher positions in SERPs. Also, if you're logged into sites like youtube.com, it will show you movies for you interests (based on what you've seen and searched for)
This is strange I have never heard of this before this probably has something to do with an algorithmic change in google.
Dial up would not be a factor for your search engine rankings. There could be some reason behind this odd scenario. And one could be signing into big G accounts as explained above.