I saw you post this problem the other day and will try to find an answer for you soon. My suggestion for now would be to use a different method of keeping track of your mileage. I would reccommend using a database app such as Docs to Go, which comes on your device. Use the Sheets to Go to make a database and then you will have your info. You would be able to transfer that file to your computer to import into a program such as Excel to print.
I have looked around, but I believe older entries of your calendar may be deleted from your device. If you want to print entries from your Blackberry calendar, my suggestion would be to do it through Google's calendar. You would need to set up a GMail email account, which is free. Then you would have access to a calendar which you could sync with your Blackberry. Then, from the Google calendar, you could print a copy of your calendar. I hope this helps.
Thank you for the response. WOW - I can't believe this is so difficult. The Palm desktop was so easy to use and utilize. Also just realized, as you stated, that my calendar is now wiped out on my blackberry so I can't get to my mileage. On the palm desktop I can go back as far as I need to review and print calendars, last saved coontacts, etc. Very sensible and easy. Also, it didn't erase from the treo to the desktop but would sync one to the other.