First make sure the card is physically inserted. Pull it out, put it back in. Battery pull. You know the basic troubleshooting type of stuff.
Options>Memory>menu button> Intall Media Card/Remove Media card (this toggles depending on what state your in)
Other memory card problem possible fixes:
Just missing stuff? When you open the media and hit explore.Goto each folder giving problems, show hidden files, and delete bb thumbs file, do a batt pull.
Options>Memory>menu button> Format Card (will erase it completely so last resort if you have stuff not backed up you want to recover, anytime you want to use a new memory card you should do this before using it)
i've rebooted the phone.
i've pulled the memory card
I have everything set to "on"
i don't have another memory card. so i'll
probably go to the verizon store
and see if it's my phone or the card.
once i do that. i'll be back and i'll give an update