We have 2 Firebox 1250e Core firewall boxes in our production environment, serving as an active and passive mode. A few months back, the active box was flashing a warning light, so our consultant removed it, and plugged it in to a test network. Everything appeared to be working fine, so he reloaded it into the production environment, and we didn't see any other issues.

Fast forward to last week, and out network was constantly dropping connections over RDC, timing out, and performing as if there was a traffic issue. I turned off the production box and everything began to work fine immediately. At this point though, I'm not sure how to proceed. Should the box be completely replaced? Is there any recommended testing we could do to determine if there is a failure of some type with this device? Should we try upgrading the software on it? I know the environment isn't the issue, since the passive box (which is now the active one) is working fine. We'd like to have 2 in production though for safety failover purposes.

I am not a network admin, but am hoping someone here might be able to provide some guidance.