I recently got a 4gb class 4 Sandisk micro sd card for use in my Nexus One. The phone performs splendidly when the card is not inserted. When ~700mb or so of music is loaded onto the card, the phone becomes very slow. Almost immediately after boot it gets to the point of being unusable (sometimes I can't even get past the initial slide-to-unlock). I can't even power it off correctly -- I've been having to take out the battery.

The card appears to be undamaged, and it works completely fine with my laptop. It appears that several people were having the same problem here: Nexus One SD card transfer problems - Android Help

Has this issue been addressed/acknowledged?