Make firefox more accepting of self-signed SSL certs
Solution 1:
You can use this addon to change the certificate acceptance behavior in Firefox:
https://addons.mozilla.org/en-US/firefox/addon/6843
Solution 2:
Talk to your sysadmin. They can setup a CA on your domain (assuming a Windows network here). Have the dev servers use certs from that internal CA, which will be trusted by all machines on the domain.
Solution 3:
One thing you might want to consider doing is to simply self sign a wildcard certificate for use on your development network. Then install that wildcard cert on all the systems. Once you accept the certificate once it should be good everywhere.