LWIP lockup on STM32

I have been having an issue in my project with LWIP. I am using a ST32F4 MCU and running with no OS. The network seems to run fine, the protocols all work, but then (usually a day or two later) the stack just stops running. It seems to happen when trying to make a new connection, but I can't confirm that because I haven't been able to locate what is causing it in the code.

Has anyone else come across this issue? I think it may be the same as this guy.