Problem - K750i is mixing up multi-part text messages

[X10]

Hello guys'n'gals,
I'm having a problem with my Sony Ericsson K750i that I hope someone out there can help with.
Over the last 4 months my mobile phone has been mixing up chunks of multi-part SMS/text messages with others.
The phenomenom only seems to occur when I've turned the phone off then back on again.
So for example, I get 2 texts, say they are 3 SMS's in length each, I can read them fine, they look fine, but if I turn the phone off, then turn it back on again some time later they will be jumbled up.
So perhaps the third part of the second text/SMS will be at the beginning in the first text/SMS.

e.g. Text 1 - Hello how are you it was good to see you?
Text 2 - I forgot my umbrella last night, can you bring it tomorrow?

Will end up as:

Text 1 - I forgot my umbrella last u it was good to see you?
Text 2 - Hello how are yonight, can you bring it tomorrow?

This is becoming annoying as a) Just in general for reading back text messages at a later date and b) I need to backup some of my text messages and it's almost impossible to do (Using the program MyPhoneExplorer) that without backing them all up and then sorting them out in Notepad.

This only seems to occur in the Inbox.
Sent messages that I write as multipart messages appear to be fine, and if I copy them to the Saved Messages folder they seem to be fine too (Saved messages saves to the SIM Card and only has space for very few messages.

The problem also does not occur with text's/SMS's under the 160 character limit (i.e. A single text/SMS).

Does anyone have any clue or idea about this issue, had it happen to them, got any suggestions??

All help is greatly appreciated.

X10

[MadduckUK]

weirdest thing ever! never ever had anything like that happen. all i can suggest is make sure your running the latest firmware

[Lucio]

You say, at some point later, could it be the linking factor could be the backup software you're using?

[X10]

MadduckUK - I was running the latest firmware up until last month I believe. But I had that firmware for ages before the problem arose.

Lucio - Possibly, it crossed my mind, but how would software on the PC affect the way my mobile is storing Texts/SMS's?
And if that is the case then how can I correct the problem (as it occurs without connection to the PC & backup software). And why would I be the only person noticing this issue (as the software is designed with K750i users in mind)?

There is currently only 1 person sending me long messages, is it possible that the way their phone constructs multipart messages and sends them to me is the problem?

X10