Hiya folks! Time for some (rather convoluted) history!
The problem of an older version of PSTK being on the path happens when you have an install of Data ONTAP PowerShell Toolkit 3.2.1 or lower on your system and you install NetApp PowerShell Toolkit 4.0 or higher on the system.
Because 4.0 seems to be a natural upgrade to 3.2.1 what many people miss is - the product (& hence product GUID) has changed. Data ONTAP PowerShell Toolkit (henceforth PSTK) used to be released as a standalone module/installer till version 3.2.1. When PSTK version 3.3 came along, it was packaged along with SANtricity PowerShell Toolkit module to produce a single NetApp PowerShell Toolkit installer (henceforth NPSTK). This new product's first release was versioned 4.0 (no, don't ask me why. May be because confusions are fun?).
Since these are two different products to the Windows System there's no 'upgrade path' between them. Playing nice, NPSTK adds it's install path to the end of PSModulePath. So the older PSTK install remains first in the path and causes the issue. The engineering team is working (based on the community feedback) to find a workaround - at least prompt the user to remove existing PSTK installs before making NPSTK installs.
Now for the more confusing part. Though we have an unified installer package for all NetApp PowerShell modules, the modules are still essentially independent of each other (and can be installed independently). So each module maintains it's own versioning, while a different versioning is maintained for the installer. I wish I could add a table here, but here's a CSV instead.
NPSTK Version, DataONTAP module version, SANTricity module version
4.0, 3.3, 1.1
4.1, 3.3, 1.2
4.2, 4.0, 1.2
Which is why the Data ONTAP module's release notes mentions the version as 4.0, even though it was installed by NPSTK version 4.2.
Hope this makes (some) sense!
Aparajita