I'm loving mycelium wallet and am recommending it to people who ask me what to use.

I've got a question about broadcasting transactions from mycelium wallets.

Sometimes when I send a transaction it takes a while before it is broadcast to the bitcoin network.

I've noticed that whenever this delay happens, the delayed transaction is always announced just after a new block is found.

My questions are

- is it really a delayed broadcast or am I mistaken in my deduction from my observations?
- why is the delay happening?
- is it unique to mycelium or is it something that can happen on any wallet?

This has affected me in a contrived test environment when sending lots of transactions in a row (and is how I have been able to correlate a delayed broadcast with a new block being found).

I almost wrote it off as something that won't affect real-world use cases, but this did affect me today in real life when I bought something at a shop with mycelium, then ten minutes later I bought another thing at a different shop and the second transaction didn't broadcast. I loaded blockchain.info and saw the last block was about 20 minutes old. As soon as the new block was found, my second transaction was announced.

First transaction - https://blockchain.info/tx/2ce67ec3f2e5d63625d809bc0f513036273dce6fd68691590eb940ef02e79c6f
Second transaction - https://blockchain.info/tx/bfe8801f7779ca18dbb6f387784f2d898f00e0929e80b28d27c36780558f5c75

I should clarify when I say 'broadcast to the bitcoin network' I mean that I can see the transaction with zero confirmations on blockchain.info or in the destination coinjar.com wallet. When it is 'delayed' I cannot see the transaction on either of these services at all.

Any help in understanding this is much appreciated.