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Bitcoin also has a tendency to lag up after ~400 transactions in 48 hours.
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If you mean the standard bitcoin client ... nope I've never noticed that.
Is that a GUI issue?
I use the daemon, not the GUI (on linux a Core2 Duo E4600 2.40GHz with only 2GB RAM)
Runs for ages - and since I last restarted it (18 days ago) I've done ~900 txns