Black screen?

[jarvis24]

[edited from support email]

when I start to run an experiment/questionnaire file the screen is all black. this happened while I was testing a questionnaire file. Under "Preferences" I get the following message "Run-time error 3343"..."Unrecognized database format 'C:\MediaLab\Styles\temp.mlp'. I went into the Styles folder and there are 2 extra files corresponding to "default" and "temp"...which are Access record-locking files. Should I re-install?