Valid sparsebundle is damaged when accessed over SMB

Hello everybody,

I am not sure whether my case is related to OS X software itself, or Cisco E3200 router, which USB disk feature I am using as a network file repository, but here is the scenario:

• Disk is 600GB Toshiba, single partition, formatted as HFS+
• On this partition there is quite large (30GB+), encrypted Data.sparsebundle located
• If I mount sparsebundle locally (disk is connected via USB) on MacBook Pro running OS X 10.8 - everything is fine, data on mounted volume is correct and "Verify disk" passes without problems
• If disk is attached to Cisco E3200 and seen on MacBook as a SMB network share //CiscoE3200/Archive, and my Data.sparsebundle is mounted from this share, then strange things happen to its content: some random files, scatterd among directory tree are reported as 0 bytes, with mods set to r--r--r-- and extended attribute of com.apple.FinderInfo attached. Moreover, the volume is reported as damaged after trying to "Verify disk". Message of error is "Invalid record count".
• The problems are in no way permanent. As soon as I attach disk back via USB and mount sparsebundle locally - everyting is absolutely fine.

I will be very glad for some tips. I really wish to use the disk via network, not locally.

Thanks in advance

Kuba