I have found a possible gremlin in the way that floating point numbers are displayed in TAdvspinEdit.
To reproduce, create a blank app with at least 2 AdvSpinEdit controls, both of which have EditAlign set to eaRight (or eaCenter), SpinType set to sptFloat and Precision set to 2.
Running this app, simple tab between the two controls and you will see that the decimal text is lost. When editing the text is shown correctly.
I should add I have the TMS Component Pack installed, and are running Delphi 7 on Windows 7. Same problem is not present when running Delphi XE2 on Windows 7.