I have the original post on DD-WRT forum and have received no reply. The more I digged into this on WinSCP forum, the more I believe the problem in downloading large file lies (even for < 2GB) with WinSCP. Have any of you experienced the same or similar? Uploading the same large file works with WinSCP and I am using "binary" transfer for both download and upload.

-------- Original Post on DD-WRT forum ---------
I am using DD-WRT build 15778: Firmware: DD-WRT v24-sp2 (11/21/10) big and WinSCP 4.2.9/4.3.1 beta. I am consistently getting "Host is not communicating for more than 15 seconds. Still waiting..." error in WinSCP during larger file transfers (< 2GB) FROM my WD 250GB USB drive (connected to Asus RT-N16 router) TO multiple PC's. The transfers always stop at around 400-500MB. During the transfers, the router's free memory drops from 120MB (RT-N16 has 128MB total memory) to 4-6MB's and stays there. The router gets reset on a few occasions when the problem arises. Interestingly, transferring the same large files FROM multiple PC's TO the same USB drive via WinSCP does not exhibit the same problem, and the transfers are always able to complete.

Is anyone experiencing the similar/same issue -- is this DD-WRT firmware related? This problem can be replicated using both WinSCP 4.2.9 (latest official release) and 4.3.1 beta (build 1099).

Thanks in advance!