[SQL 2008] SQL Won't Always Save Data Until Software Is Restarted

My application pulls some data from SQL when it is started. At the end, it then saves a bunch of data.

Sometimes, it will work just fine during load. But during save, it won't save the data. It will give the generic, "Can't connect to SQL" error. Releasing and renewing the IP of the unit sometimes work, but not always.

But, if I close the software, open and then skip everything, it saves just fine.

Has anyone experienced any issues like this before? Could maybe a rogue open connection be causing the issue?

Thanks