user1891: 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. 

user2995: You have to spend your bitcoins in small amounts. I don't think there is any other way. Try to send as large as possible to pay less fees.
This piece of code is preventing QT from sending transactions that are larger than 100Kb. 
unsigned int nBytes = ::GetSerializeSize(*(CTransaction*)&wtxNew, SER_NETWORK, PROTOCOL_VERSION);
                    if (nBytes >= MAX_STANDARD_TX_SIZE)
                    {
                        strFailReason = _("Transaction too large");
                        return false;
                    }
                    dPriority /= nBytes;

MAX_STANDARD_TX_SIZE is MAX_BLOCK_SIZE_GEN/5 and MAX_BLOCK_SIZE_GEN is 500Kb.

user6454: 
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. 

1891: <p>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</p>

<pre><code>transaction creation failed
</code></pre>

<p>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.</p>

<p>I tried to restart the wallet but this still happens.</p>

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

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

<p>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).</p>

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

<pre><code>Transaction too large
</code></pre>

<p>and right after it another one</p>

<pre><code>Error: Transaction creation failed!
</code></pre>

<p><code>P.S.</code> just few days ago I updated the client to <code>v0.8.5-beta</code> but the problem still exist.
I really want to spend my bitcoins, but can not do this. I also tried different addresses. </p>
 2995: <p>You have to spend your bitcoins in small amounts. I don't think there is any other way. Try to send as large as possible to pay less fees.</p>

<p>This piece of code is preventing QT from sending transactions that are larger than 100Kb. </p>

<pre><code>unsigned int nBytes = ::GetSerializeSize(*(CTransaction*)&amp;wtxNew, SER_NETWORK, PROTOCOL_VERSION);
                    if (nBytes &gt;= MAX_STANDARD_TX_SIZE)
                    {
                        strFailReason = _("Transaction too large");
                        return false;
                    }
                    dPriority /= nBytes;
</code></pre>

<p>MAX_STANDARD_TX_SIZE is MAX_BLOCK_SIZE_GEN/5 and MAX_BLOCK_SIZE_GEN is 500Kb.</p>
 6454: <blockquote>
  <p>Transaction too large</p>
</blockquote>

<p>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. </p>
