PHone stalls and won't read SD Card

restart the phone

It might just be the sd card try getting a new one if that dosn't work then try sending for a new sd reader and swap the two out.

NO.
Just buy a new card since trying to fix it may later have long terms effect on the phone

If your SD card cannot be formatted and your phone cannot read it, you will simply need a new SD card. That is the only fix.

-ex Sprint rep

Try using another SD card to see if that one will read. If so, there is a problem with your SD card.
But if that card is also unable to be read, and your phone is fully updated, there is a problem with the reader on your HTC handset. You can contact HTC for a repair or a replacement. You might even have some luck at the retailer where you originally bought your phone. It's a fairly new model.

Here's HTC's number:
866-449-8358 6am-1am Eastern Time

HTC sucks or atleast HTC P3300 sucks.... i am having that phone and its giving lot of problem... about sd card.... it had withme also i it was not working in my phone but in othere it was working fine but anyways i changed to new sd card and that stupid phone was able to detect that new card....

either the card is not supported or it needs formatting

What size is the SD card in GBs? If it is larger than 2GB (4 or 8) do you have a SDHC card reader?
Also try formating the card first in the phone and then using it. Using it straight out of the package, while able to be written, my have difficultly with other devices reading the data.

i was told at a vzw store that they make upto 4g in micro sd cards and they will work a have a 1g and it works fine