There's just too much info needed to be saved. If it's simply transferred over to the new profile then it works for a short time then the corrupt files wreck the new profile.
This isn't an attempt to provide any kind of definitive answer but your description begs a number of questions...
#1 - What kind of email account is this particular PST file associated with - POP3 or IMAP?
#2 - If IMAP - am assuming that the PST file in question is related to the one which contains the <Inbox> folder> correct?. Simply deleting (renaming) this file will result in a new one being automatically recreated with the contents of whatever
exists on the server (assuming you have no created any kind of <local only> unsubscribed folders in the tree) - which then begs the question as to whether or not the root of the problem exists within the data stored on the server
#3 - If POP3 - what is the format of the PST file - ANSI or Unicode? If ANSI - what is the size of the file? ANSI files max out at 2gb
To determine the format - right click on the root of the PST file --> properties --> click <Advanced> button --> if the <Format> field description contains <97-2002> - it's an ANSI based PST file. (Regardless of anything else - if
this is the case - should be converted to a UNICODE file)
#4 - Where is the PST file being stored - on a local drive or a network drive? If network - not supported and highly prone to causing corruption.
#5 - Purely from a logical perspective - the fact that things appear to work properly for the "first few days" after a new profile is created indicates that there is something consistently occurring on some kind of 'timed basis" triggering
your issues. If that's the case, even if ScanPST did fully clear all issues - just a matter of time before the same thing happens again (whatever "that thing" may happen to be) - ergo, in this scenario, highly unlikely that ScanPST is the answer
since what really needs to be done is to find the root cause of what is triggering the problem.
#6 - It would also be pretty safe that this is not a generic issue impacting everyone using OL'2010 - regardless of OS so your environment is one deserving a lot of close scrutiny.