T42G Will not update firmware

[itdweeb99]

We have an office of about 15 T42G phones. All of these phones are running firmware 29.73.0.45. I'm having a weird issue with action URLs getting truncated. Yealink recommended that I updated to the latest version of firmware. I downloaded the latest version and attempted to apply it to 3 different phones. None of the phones seem to take the new firmware. The phone acts as though the upgrade goes through properly but when I check the firmware, it still shows the old version. Yealink is closed for 2 weeks or something ridiculous so I can't get a response from them. Any ideas as to why the firmware won't take? I've tried several different versions including 29.80.0.60 and 29.80.0.70. Both had the same result on all three phones that I tried.