See if this helps you..

 You cannot go beyond 1000 waypoints, but you can fill the card with POI's

 Here is a forum topic on groundspeak about just this such thing.

http://forums.groundspeak.com/GC/index.php?act=ST&f=11&t=140808

On 9/10/07, Richard Daines <rjdaines@gmail.com > wrote:
Regarding a 2 Gig card, my 60CSx read the card but I certainly could not load up the whole thing with maps.  Not sure if it's my problem or the units limitation.  I'm not really interested in loading POIs and tracks on it.  It would be really nice to break the 1000 waypoints limitation with the card but I think they are all stored on internal memory.


On 9/10/07, ShadowAce <shadowace.az@gmail.com > wrote:

Question:  What is the largest size microSD card that I can use in my X-series GPS unit?
Answer:

At this time, the 2 GB cards are the largest microSD cards that can be used for the X-series GPS units. However, the X-series GPS units are not compatible with the San Disk Ultra II cards and therefore we do not recommend using the Ultra II micro SD cards with any of the X units.

Last modified on:  06/01/2007
 From Garmin