XBee transmission lag

Hi,

I have a very unstable transmission XBee problem. (XBee Pro S2: XBP24-Z7CIT).

Sometimes it works as good as it should be but 60-70% of the times there are extremely noticeable lagging.

I used 9600 baudrate, 8 bits, no parity, 1 stop bit.

Xbee is connected to PIC as end device and send the data to a PC with XBee as coordinator.

Thanks