bind becoming stale

Hi,

We have had a problem for a long time where the bind/s becomes stale i.e
can't send an SMS but the transmitter and receiver are up. In theory the
enquire link should drop the binds and restart them but this does not
happen. Below is my smsc config.
The only indication I have of this problem is the store file starts to fill
up. I'm not sure if this a bug or others have the  same problem.

The only thing I can try do is use a script and add lynx -dump
"http://localhost:13000/store-status.xml?password=passwordused&smsc=smscid"
and take a count of the SMSs in the store if they are greater than a certain
value, then restart the bind. Is this a reliable approach?

Any other ideas appreciated.

group = smsc
smsc = smpp
smsc-id = smscid
allowed-smsc-id = smscid
host = host_given
port = port_given
receive-port = port_given
smsc-username = username_given
smsc-password = password_given
system-type = SMPP
reconnect-delay = 40
enquire-link-interval = 15
validityperiod = 4320
source-addr-ton = 1
source-addr-npi = 1
dest-addr-ton = 1
dest-addr-npi = 1
msg-id-type = 0x01
throughput = 100
max-pending-submits = 10
connection-timeout = 0

Rgds