No, the proper way to check the version of PSQL installed, beginning with PSQL v10.0 and later, is from the WINDOWS control panel (Programs and Features or Add/Remove Programs). I am not referring to the Pervasive PSQL Control Center (pcc.exe), as BtrieveBill [correctly] pointed out, the "Help-->About" dialog in PCC only shows the version of the individual PCC component (pcc.exe file version).
If you've successfully installed the patch on the server and the version information displayed from the WINDOWS control panel does not show "10.31.044" then that is a bug. However, that information is verified by Pervasive before the patch is published so it should be correctly displaying "10.31.044" for v10 SP3 Update 20.
The method described in the document referenced by BtrieveBill will allow you to see the specific component version for the mentioned PSQL engine files (the file version of the installed components or "10.31.37.0" in the case of ntmkde.dll for v10 SP3 Update 20). However, Pervasive does not currently publish the individual file versions as they are different from the actual PSQL product version and they are different depending on which component/file is being checked (engine files, Pervasive services files, third-party components, etc.). The only version information published on the Pervasive website is the PSQL product version, which should be correctly updated in the WINDOWS control panel after each patch is successfully applied to the system.
If you have successfully applied the v10 SP3 Update 20 patch to your server installation and you do not see "10.31.044" listed as the product version in the WINDOWS control panel (Programs and Features or Add/Remove Programs) then that would indicate a valid issue with the latest v10 SP3 Update. In which case, please respond with more information regarding you specific PSQL configuration (including what OS version the server and clients are installed on and whether or not v10 SP3 was the first version of PSQL installed or if it was upgraded from an earlier version of PSQL) and I will open a change request with Pervasive support to have the issue fixed.