I don´t get it...

Opened a Tumblr account on my PC, to follow some blogs I like. Made a note of the essential data in my very privy book of memory aid, tried to log in the next day...epic fail. Wrong password, I was told. Reset my password, made a new one, wrote it down, next day epic fail number two. Wrong password, again. Reset again, tried again, failed again. I must confess I do not keep a browsing history on my PC, so I have to log in anew each time I want to open my account. I do not keep a history on my tablet PC, either, but I had no problem in opening my Tumblr account using yesterday´s password on the tablet while it did not work on my PC. Wrote a mail to Tumblr, got a mail back, to reset my password. No kidding? New password for each time I want to check my account? Anyone out there who has had the same problem and found a solution?