I'm still running 2.0.28 , so this may not be an issue with the new version, however I saw one post still reporting shares problems so I thought I'd post this observation.
Since I installed 2.0.28, I haven't had much problem with lost shares, except for a couple occasions where an application apparently crashed. However, yesterday, I observed something that may not be important, but I found it interesting.
The network I have my Roku on usually only has 1 computer, one TIVO, and a Netgear music device, so generally there is little or no activity on the network. What happened, was that I wasn't even actively using the Roku at the time, although I think I had a telnet window open, but I had put a second computer on the network several hours before the problem occurred, but only made some very quick network tests.
However I decided to experiment by streaming a big video file from my main computer with VLC to this second computer, which also had VLC running. I was trying to compare how the Roku talks to VLC while streaming vs how VLC talks to VLC while streaming, by using a network sniffer.
Well shortly after starting my stream to the second computer, things got clogged up, and I had to terminate the process, but after stopping VLC on both computers, I noticed that the network had gone bezerk with activity going out on all ports. I turned on the network sniffer, and the Roku was searching for computers on all possible IP#s of the subnet it is on, ie basically sending out "who's there" pings on x.x.x.1 x.x.x.2 x.x.x.3, etc. I tried to access the Roku by telnet, and I couldn't get a listing on my shares. Ran upstairs and looked at the Roku display on the TV, and there were no shares listed at all. Went into the nework shares window in the setup screen, and it had listed a whole bunch of new shared folders that were on this new computer I had on the network, but nothing unusual.
Only thing I can figure, is that the Roku must have detected the presence of the 2nd computer and catalogued all the shared folders, however somehow my streaming to the 2nd computer somehow caused enough network congestion, that when it tried to do a periodic check of the shares, it must not have gotten an answer, and decided to do a complete check of all computers on the network for some reason. It should NOT have had any problems getting through to the main computer, but it may have had problems getting through to the 2nd computer, which is slower, and wasn't capable of displaying the video I was sending it.
Anyway, whatever the reason, I found it interesting that network congestion not even visible to the Roku (since it was through a switch, and the Roku light wasn't even lighting up) would cause the Roku to go beserk and lose it's shares. I also found it interesting that it was going through each IP# one by one, instead of sending out 255 requests that go to every computer at once, which I thought was the way it was usually done. I just thought that some of the lost shares problems that some people are reporting might be caused by network congestion not even involving the Roku.
BTW, everything on my LAN uses fixed ip#s.