Bad working buttons

Hello! I m using my sansa for a bit long time, like one and half year. 
And now that suddenly happens! PAM! Bad work of upper button and botton button :s 
The porblem is that I sometimes must press these buttons so strongly to let them work once. I cant scrool now :s
but Sometimes they work nice and I dont need to use any power to trigger the button, but mostly I need to squeese my Sansa Smiley Wink
Is it normal after that time of using this MP3? (left and right buttons works nice… Still…)
Ah and one more thing - sometimes happens double-clicks… that s so annoying sometimes :s

By any chance, are you still under warranty (1 year U.S., 2 years EU) so as to get a warranty replacement?

Yeah, but I lost my receipt/ warranty card :s and I dont know others capabilities to use my warranty without receipt :s

All you need is the receipt.  By any chance, did you charge the purchase on your charge card and can you get a copy of the charge card statement (my credit card company keeps the statements available online for a year or 2)?–SanDisk might accept that.

At any rate, you might want to contact SanDisk about the situation, regardless–you never know what might happen, until you try.  The Contact info.:

http://www.sandisk.com/about-sandisk/contact-us/

Then probably the hope isn’t gone xD thanks