MIFARE_Ultralight_Write command giving timeout in communication error

[krulkip]

I am using the line below to write to an ultralight-c card. I know that this works because i have another program which works correctly.
When i use it in my latest program i get timeout in communication error and cannot figure out what is different.
I think the ultralight card has to be put into a certain state before you can write to it.
I tried

bsize = sizeof(buffer);
MFRC522Extended::StatusCode status=mfrc522.PICC_WakeupA(buffer, &bsize);

Does anyone know what commands need to be given before you can use the MIFARE_Ultralight_Write command ?

MFRC522::StatusCode status = mfrc522.MIFARE_Ultralight_Write(page, &Buffer[0], 4);