After Lion upgrade Time Machine backups not dependable

[JustM3]

After upgrading to OS X Lion my time machine has regularly lost contact with time capsule, it always says unable to find backup disk. I have performed full reset four times- it reconnects, it work for some time. i have backup of 1 week. anyone having any idea what can be underlying trouble?

[Aniela]

I think your using OS X LIon 10.7. if that is true you should upgrade to most recent version os x lion 10.7.2 which might resolve your trouble.Do let me know if you have any other trouble

[Jezriah]

Follow this steps

On the Time Machine Preferences window, click the Options button.
If you're backing-up to an external HD, eject, disconnect, and power it off for a few moments, then reconnect it.
Remove the file /Library/Preferences/com.apple.TimeMachine.
You may have to navigate to it;   a Spotlight search won’t show it, and a Finder search won’t, either, unless you include System Files.
Go back into Time Machine Preferences, re-select the drive, re-enter any exclusions and other options you noted in step 1.
120-second countdown to a backup should appear.  If you close the window, it should begin immediately.

[Ticod]

In my knowledge (and with all due respect to Pondini) Time machine has never been reliable sufficient to warrant relying on it as a sole backup method, admittedly very few method are (maybe none) so always have option.

I'll step aside for Pondini to notify you better.