The 74tjump patch described earlier has an overflow problem, and I think that it's not really a simple enough fix.
The 74tjump2 fix is conceptually easier to grasp: for packets sent more than 250 milliseconds ago, according to the gettimeofday time, instead use a jiffies-based time. This change requires an extra datum per "frame", the data structure that tracks an AoE command, to record the sent time in jiffies.
By subtracting unsigned integers, the jiffies time calculation avoids overflow as long as the time difference is not more than 2^32 jiffies. That's about 1193 hours on a machine with HZ set to 1000.