May be the cause is the ssh tunnel. I have uploaded a new release (0.1.6-1) to the repositories which adds an option ("-u") to use a direct connection to the host. Please, try it, but beware that, although the session is started using ssh so the account credentials are not sent in the clear, the data connection is unencrypted. Furthermore, you have to allow incoming connections to tcp port 5011 in your host.
1 upgraded, 0 newly installed, 0 to remove and 5 not upgraded. Need to get 8236B of archives. After this operation, 0B of additional disk space will be used. Get:1 http://repository.maemo.org fremantle/free snx 0.1.6-1 [8236B] Fetched 1B in 11s (0B/s) Failed to fetch http://repository.maemo.org/extras-d....6-1_armel.deb Size mismatch E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?