I have the similar problem.
I have Solo2 connected through GBE switch to Synology DS213.
I chose BH image because it perfectly supports Sony’s PlayTV DVB-T dual tuner.
When I installed any newer image BH 2.1.x (with new kernel 3.13.5) my network slowed significantly, for example playback of recorded movie from Synology mounted with CIFS has frequent freezes. I reflashed BH 2.1.0,1 and everything is OK.
The similar problems specific only to certain versions of the Solo2 were observed with VTI 7.0 image and Vuplus team released patch of kernel yesterday.
There is very long thread on the VTI support page dedicated to the slow network with kernel 3.13.5 and Solo2.