Randomly Resending Texts?

[MrBeefy]

This has just recently started to happen on my girlfriends phone. Randomly, it will re-send old messages to random people. I received 4 messages that I had received previously, some as old as about 3 weeks. She is using the EC05 stock rom, unrooted, and she is using Handcent. Is this a problem with her phone of with the application? I am using the same set-up as her, and I haven't yet experienced this issue.