Unable to Install FRING and NIMBUZZ ON nokia 5800

i had the same prob with my 5800 i went to nokia care n they told me this is problem of ur service provider n i was using vodafone so when i tried using qtel sim it really worked now im using both software like fring, nimbuzz or facebook....or try it with offline mode...

hope it helps

check the details on the certificate that gives you an error. see when the certificate was made and when it expired... then try changing your mobile's date to any date which falls between those dates... now try installing your app again.

i had both fring & nimbuz on my phone before but in between i wasnt able to instal any other program with same msg cert expired so reformated the phone. But now even couldnt install fring or any other soft ware as same like u