Seems like my wallet is stuck, been at block 715128 for 121 days now with 35 active connections. Checked firewall and re-installed once. Did we have other solutions ? I know it was somewhere in these 250 pages

I have the same problem, wallet just gets stuck and wont sync. Has happened a few times, forcing me to sync from scratch.
Its a total pain in the @r$e, frankly.
Is there a current SLG chain available that can shorten the sync time??
Sterling SentinelSnapshotting would be the fastest way,
http://Sterlingcoin.org/SterlingcoinSnapshot796871.zip (~372 MB) Extract and overwrite those contained files into your Sterlingcion data directory ( %appdata%/sterlingcoin/ or ~/.sterlingcoin/ ). Delete the peers.dat file. Start the wallet and allow it to fully sync. This snapshot is 2 months old, but should give you a very healthy head start.
I suspect this might be occurring for people because few coins are being consistently staked on the network. Difficulty drops very low and many wallets submit a block to the network at about the same time. This flood of blocks across the network forces 'islands' to form and be built on faster than consensus agrees across the network. The islands become locked.
We need more coins constantly staked I believe. I am acquiring as many as I can and staking them 24 / 7.
Please verify your chain against the explorer and stake your Sterlingcoin as often as possible.
EDIT: Linux or Pi users: the above snapshot is of the data files from a machine with DB 6.1. Earlier versions of Berkeley DB will not read it. Windows and mac users: your wallet uses DB 6.1 already. The snapshot will work fine for you.
CWI have our new servers commissioned - and are currently building them ...
next week - the slg seednodes will have a new home and will be fully functional once again ... the cramped and intermittently ceased small nodes they exist in now will be a thing of the past - as more and more nodes are added as we migrate the wallets to the new dedicated servers ...
now all we need are coins to fill the nodes with - and we will have the 'standard' level of seednodes that is expected in the CWI-SeedNode infrastructure ...
more will come in the coming months ...