Had the exact same problem with Antivirus (from Avira). My complete access to the burst wallet folder was denied and I had to delete the virus scanner and dispose of the "burst_wallet.exe" (couldn´t make the virus scanner to accept an exception). Did then reinstall the scanner.
Had a bad feeling about this and decided to use the normal wallet client in future. I must admit, I still fear that my PC may be infected with something now.
edit:
Above text sounds a bit harsh. I have to add that I don´t think the developers added a trojan on purpose. Most likely it is a false positive.