I'm Olivier developer of Wisespent.
No it is supposed to work.Even with the trial version.
Your OS is ok and model too.
The problem you are facing is a well-known bug that faces third party applications such as mine. Some large providers (such as Tmobile and so on) use a Blackberry mail server that deal extremely bad with third party applications sending attachment.
They keep Blackberry tags in the email. They don't filter them out as valid MIME code (the ones that will be understood by your email reader)
RIM told me that they plan to fix the bug in next versions...
In the meantime...There is a solution
I guess you are probably using a Webmail application or something else.
Outlook is able to show you Wisespent attachment. The emails you will received will show you some "weird" filenames such as "file0001.dat". Simply save them on your hardisk they are valid CSV file. You can still import them into excel and print/save data.