mysql inserting decimal value with perl loses precision

[myrose . 20 . ftumsh]

Lo,

This is more for the archives than anything as there is a workaround.
When inserting 1234567890.123456 into a decimal(16,6) column, the value 
stored is 1234567890.123460

Having a brainwave from the Time::HiRes docs,
sprintf('%.6f', 1234567890.123456) stores the expected value.

Is this expected behaviour or should DBD::mysql automagically do the 
right thing?

John