wp.org vs wp.com, can’t log into wp.com for stats

Please explain to me what is going on here…
I upload the blog stats plug-in to my blog. Everything seems fine.
I upload the plug in to a new blog. Every time I try to enable the plug-in I’m asked to log-in. I can’t. I get invalid password. I noticed that there is www.remarpro.com and the stats are run off of wordpress.com.
It seems like I have more than one profile and I’m getting confused and super frustrated that now I can’t seem to check the stats on any of my blogs because I’m constantly asked to log-in to see them and I’m continually denied.
Can someone help to “get” what’s going on here please?
Thanks.