Transferred calls show extension s instead of extension number

[cursor]

I am having a problem tracking transferred calls.  They are shown in the reports but only external transfers (outside the call center) show the number dialed.  When the call is transferred to an internal extension I just get "s" as the destination.  Why would this happen?  The only thing I can think of is that my internal extension macro uses s to process the call.  Any idea on how to correct this?  I am using plain Asterisk 1.8 on Centos.  All dialplan logic is coded by hand.

[QueueMetrics]

How do you do the transfer? the issue is that QM will of course report on what is logged....

[cursor]

Transfers are done using the SIP phones transfer button, not with the Asterisk function.  Here are some log entries for transfers:

1379433548|1379433498.2515|ventas2|SIP/1527|TRANSFER|s|macro-stdexten|7|42|1
1379438586|1379438459.3325|ventas|SIP/1513|TRANSFER|s|macro-stdexten|1|124|1
1379440824|1379440639.3638|ventas|SIP/1513|TRANSFER|s|macro-stdexten|1|183|1
1379541764|1379541247.14829|ventas5|SIP/1729|TRANSFER|952017800|oficina|4|512|1
1379686450|1379685157.6295|RCI|SIP/1902|TRANSFER|952831111|oficina|35|1249|1

The ones that go to internal phones using the stdexten macro are the ones reporting s, calls to outside phones do have the correct number.

[QueueMetrics]

What does the agent enter when do do an internal transfer?

[cursor]

They press the transfer button on the phone and then dial a 4 digit extension number.

Extensions are defined in the dialplan as:

exten => 1501,1,Macro(stdexten,1501,SIP/1501)

[QueueMetrics]

Trying not to use a macro, just for testing what gets logged?