I've upgraded hundreds of mx-one 3.2 to 4.1 and then to 5, between mx-one versions 3.2-5 the SLES also was upgraded, so it must be upgraded also.
To upgrade with Recovery Dvd, you need to make PCREGEN from the old version 3.2. You need an version of PCRegen that has as source MXone 3.2 and as target system mxone 5 or 4.1. After you take the PCREGEN you reinstall the PBX from the Recovery DVD and you make ts_startup step. After you passed ts_startup and inserted your PBX IP's, you upload(I've used WinSCP) on the PBX the target folder generated by PCREGEN then you run the following commands in Putty after you've uploaded your license file!:
your_PBX# cd /pcregen-target-directory-uploaded-by-you
your_PBX /pcregen# dos2unix REGENCMD.TXT
your_PBX /pcregen# mdsh -c /pcregen/REGENCMD.TXT |tee /pcregen/PCREGEN_LOG.TXT
You should wait for the PBX pcregen to upload on the system, also you could check the log file to see if something was not imported.
The upgrading procedure from upgrading package mx-one 5 is more elaborate and it supposed that you upgraded the SLES packages to the last version and also upgrade SLES version to SP4 minimum, then run the mx-one 5 installer archive. But this method is more advanced as you need to have knowledge about Linux