If you are working on a project with a partner and using two different measuring tapes, take the time to check that both tapes are in synch. Sometimes if the hook end of an older tape happens to get bent, it may throw off the measurement as much as a sixteenth of an inch. That error can be enough to cause problems if you need to do precision work. To doublecheck two metal measuring tapes for accuracy, mark a line at a certain distance on a board, draw the tapes out and compare readings.
Several methods are available for dealing with screws that tend to vibrate loose on covers of equipment such as chainsaws. One good fix is to remove the offending screws and wrap 1/2-in.-wide Teflon tape around the threads and then screw them back in. The tape will hold the screws tight, yet will allow you to remove them when necessary.