Limits on older GPSrs

[maps4gps]

I have placed about 1-1/2 Gb from a mapset on a 4Gb card (only data on the card).
I do not have a 2Gb card and my 76csx will not use the gmapsupp.img if I place it on a 4Gb card. 
Do the older models have a 2Gb maximum card size, or is there some other reason the 4Gb card can not be read?

[Indrid Cold]

There was a firmware update that took care of that with the GPSMAP 60 series, sould be the same for the 76 series also I would think. Firmware up to date?

[Seldom]

Here's the link if you need it.
https://support.garmin.com/support/searchSupport/case.faces?caseId={9dec4ad0-954a-11dd-f60b-000000000000}
I remember something old about Sandisk cards having a problem.

[eaparks]

I know you are aware of it, but are you sure the card is formatted FAT32? I had a problem once where my 60CSx would not read the map until I reformatted the card.