Reading from a FIFO with DMA

Hello, I am trying to use a DMA to read from a FIFO. To see if this is working I write and read from the same FIFO, expecting to see always the same data, but I see only half of them! It seems that the FIFO outputs data faster than the DMA is expecting, for example:

Input Output

0 0

1024 2048

2048 4096

3072

4096

I attach my qsys connections and the C program I use to drive the DMA

//writes to the fifo
//configure the DMA controller for transfer 
    _DMA_REG_STATUS(h2p_lw_dma_addr)=0; 
    _DMA_REG_READ_ADDR(h2p_lw_dma_addr)=ONCHIP_MEMORY2_0_BASE; //read from ROM
    _DMA_REG_WRITE_ADDR(h2p_lw_dma_addr)=FIFO_BASE; //write to FIFO
    _DMA_REG_LENGTH(h2p_lw_dma_addr)=4*100;  //write 100x 4bytes
 
    //start the transfer 
    _DMA_REG_CONTROL(h2p_lw_dma_addr)=_DMA_CTR_WORD | _DMA_CTR_GO | _DMA_CTR_LEEN | _DMA_CTR_WCON;
//reads from the fifo
//configure the DMA controller for transfer 
    _DMA_REG_STATUS(h2p_lw_dma_addr)=0; 
    _DMA_REG_READ_ADDR(h2p_lw_dma_addr)=FIFO_BASE;
    _DMA_REG_WRITE_ADDR(h2p_lw_dma_addr)=ONCHIP_MEMORY2_0_BASE;
    _DMA_REG_LENGTH(h2p_lw_dma_addr)=4*100;  //write 100x 4bytes
 
    //start the transfer 
    _DMA_REG_CONTROL(h2p_lw_dma_addr)=_DMA_CTR_WORD | _DMA_CTR_GO | _DMA_CTR_LEEN | _DMA_CTR_RCON;

I have tested this code writing from RAM to RAM and it works, the addresses are correct and the DMA initiates the transfer correctly, it just misses the data, can you help me?

http://www.alteraforum.com/forum/attachment.php?attachmentid=13179&stc=1