transaction creation failed I am using bitcoin Qt
version v0.7.0-beta and when I tried to send a transaction (1.5 bitcoins) I received a message

transaction creation failed


what can be the reason? Few minutes ago I sent 0.1 bitcoins and it was accepted. Three hours ago I sent 0.3 bitcoins and it was accepted and received on the other side.

I tried to restart the wallet but this still happens.

P.S. I do have more than 1.5 bitcoins when I am trying to send them.

Just a few observations. I tried to send 0.3 and 0.5 bitcoins one more time and it works with both of them. 

Just tried one more time to transfer some bitcoins to another account in BitCoin Qt (version v0.8.3-beta - the newest at the time of writing).

This time I am getting some additional error message, which is still is not useful.

Transaction too large


and right after it another one

Error: Transaction creation failed!


P.S. just few days ago I updated the client to v0.8.5-beta but the problem still exist.
I really want to spend my bitcoins, but can not do this. I also tried different addresses.
Transaction too large


Is your wallet made up up of many, many small amounts? Have you visited any sites giving small amounts of Bitcoin away for "free"? If so, your client is coughing up on the fact that all the small transactions are costing more than the fee they incur to spend.