Have to scan multiple times before it goes through

Hi,

My office uses 2 Xerox machines: WC5745 and WC7525. Every time I scan, I would have to scan multiple times before it shows up in my folder. I receive no error on the machines and it seems to have scanned properly. 

I do not know if its the problem with the drivers, the machines, or our network. 

I also am wondering where these lost scans would go.

Thanks in advance,

Ken