Problem with SanDisk 4GB Ultra II compact flash card

Hi,
I bought a Lexar Ultra II 4 GBytes compact flash
card, and put it in my Canon 1D Mark II camera.
It showed only 2 GB. I put it in my flash card reader
on my PC. It showed only 2 GBytes. I reformatted
it in the camera and it still showed only 2 GBytes.

I have several Lexar 40 and 80x 4 GByte cards and
have never had this problem.

Documentation with the card says nothing.
On the card it says:

[left half circle symbol] 3. - 2GB for fat 16 SLRs
[right half circle symbol] 2. - 2GB for fat 16 SLRs
[full circle symbol] 4. - 4GB for fat 32 SLRs

The 1D Mark II does fat 32 on the lexar cards.

Does anyone know how I can get beyond the 2 GB limit?

Roger