Microsoft released Service Pack 5 form Dynamics-GP 10. This service pack includes many fixes to Dynamics-GP 10 along with required payroll tax updates. So those of you that use payroll this is a required update.
A couple of important things you should know prior to applying this service pack:
If you are planning on upgrading to GP 2010 when you apply this service pack you cannot upgrade GP 2010 until service pack 1 is released for GP 2010
If you are using web services after applying this service pack you must apply the latest hotfix for web services
If you are prompted to restart you must restart and restart the service pack install. If you do not start the service pack install the UPR00300 table will fail on the update
Remember to review the complete install documents prior to performing this update.
Link to SP5 on Customer Source