Leopard Upgrade problem

I do not use time machine myself (I prefer "backup").
Couple of things though: Before installing any update, I always run disk utility.
Also, have you tried trashing the preference file of the offending app (you do not state what app it is.).
Good luck

hiya,

I do not know this app but if I checked right, is it the one by Davis Instruments.
According to the macupdate link:
http://www.macsoftware.apple.com/action.lasso?-database=macosguide&-layout=cgi_d etail&-response=/ussearch/detail.html&prodkey=24516&-search

a new version was brought out on 21 May 08.

Now, a preference file is either in the "library/preferences" of your home folder OR of your start up drive. It may also be under "library/application support".
It MAY be called something like "com.weatherlink.plist" or "com.davis.plist" (the latter, I deduct from the company name or whoever manufactures the software).
It can be something really strange (e.g. Maxon Cinema 4 d preferences are called "mca10_1017643" in my case), but they are still in the preference files.

Another idea might be to try and write to Davis Instruments.

I wish you luck.