Vista - FolderShare cannot connect

I'm currently using FolderShare (latest 14.0.1383.0530) on four Windows
computers. Three computers are at home behind a firewall (that I cannot
control) and the one at work is even behind a proxy (also which I cannot
control).

I've been using FolderShare for about 6 months now with just minor
connection problems on all computers (sometimes it takes a long time to
connect). But for the computer at work the situation has gotten much worse
and I can hardly ever connect. In fact, I haven't been able to use
FolderShare properly on my work computer for the last three weeks!

I've been trying out different settings and different versions of
FolderShare but without any luck. I've been checking the log now and then and
it always seems to be the same problem - failing to connect to the
masterserver.

Ports are not forwarded and upnp is probably not supported (beyond my
control). In the settings dialog -> Port status, it says OK on all rows in
the Initiate Connections column, and Blocked on all under Accept connections.
Proxy settings are okay.

How come it's so difficult to connect, but still not entirely impossible?

Here's a snippet of the log that might be of interest (I can also provide
full log):

--------------------------------------------------------

16:01:32.878 connection.cpp:1155!changeConnState (DETAIL): changing conn to
PRIVATE_DATA_REMOVED:443 from waitingForHttpConnect to connected, fd: 608
16:01:32.878 serverconn.cpp:8111!handleRedirectorConn (DETAIL): making
redirector request, cloudId=0
16:01:32.878 serverconn.cpp:8116!handleRedirectorConn (DETAIL): checking for
complete message, buffer has 0 bytes
16:01:32.878 serverconn.cpp:8036!parseRedirectorHttpResponse (DETAIL):
returning result 3
16:01:32.878 serverconn.cpp:8116!handleRedirectorConn (DETAIL): checking for
complete message, buffer has 0 bytes
16:01:32.878 serverconn.cpp:8036!parseRedirectorHttpResponse (DETAIL):
returning result 3
16:01:32.941 serverconn.cpp:8116!handleRedirectorConn (DETAIL): checking for
complete message, buffer has 0 bytes
16:01:32.941 serverconn.cpp:8036!parseRedirectorHttpResponse (DETAIL):
returning result 3
16:01:33.003 serverconn.cpp:8116!handleRedirectorConn (DETAIL): checking for
complete message, buffer has 0 bytes
16:01:33.003 serverconn.cpp:8036!parseRedirectorHttpResponse (DETAIL):
returning result 3
16:01:33.066 serverconn.cpp:8116!handleRedirectorConn (DETAIL): checking for
complete message, buffer has 0 bytes
16:01:33.066 serverconn.cpp:8036!parseRedirectorHttpResponse (DETAIL):
returning result 3
16:01:33.128 serverconn.cpp:8116!handleRedirectorConn (DETAIL): checking for
complete message, buffer has 0 bytes
16:01:33.128 serverconn.cpp:8036!parseRedirectorHttpResponse (DETAIL):
returning result 3
16:01:33.144 connection.cpp:2250!handleReadSocketSet (DETAIL): read 867
bytes from PRIVATE_DATA_REMOVED on port 443, r 0, w 867, errno 0
16:01:33.144 serverconn.cpp:8116!handleRedirectorConn (DETAIL): checking for
complete message, buffer has 867 bytes
16:01:33.144 serverconn.cpp:8036!parseRedirectorHttpResponse (DETAIL):
returning result 3
16:01:33.144 connection.cpp:2250!handleReadSocketSet (DETAIL): read 0 bytes
from PRIVATE_DATA_REMOVED on port 443, r 0, w 0, errno 0
16:01:33.144 connection.cpp:2293!handleReadSocketSet (NORMAL): Read 0 from
conn to PRIVATE_DATA_REMOVED:443, usingProxy: 1, connState: connected
16:01:33.144 connection.cpp:1366!closeConnection (DETAIL): in
closeConnection, sockfd: 608
16:01:33.144 networking.cpp:814!closeSocket (DETAIL): closeSocket called for
fd 608, res: 0, err 0
16:01:33.144 connection.cpp:1155!changeConnState (DETAIL): changing conn to
PRIVATE_DATA_REMOVED:443 from connected to closed, fd: -1
16:01:33.144 serverconn.cpp:7894!setReconnectTime (NORMAL): reconnecting in
2000 ms, have 1 failures, rapidReconnect: 1
16:01:33.144 serverconn.cpp:8093!handleRedirectorConn (ERROR): masterServer
conn failed. 1 failures, will try again in 2000 ms, quick: 1
16:01:33.144 serverconn.cpp:8241!handleRedirectorConn (NORMAL): closing
server conn
16:01:33.144 core.cpp:3890!coreLoop (DETAIL): skipping select, maxFD is -1