I hope your dwnld.dat file is not corrupting on a regualr basis!?? If so there's something definitely wrong. What OS version & Java version are you using? Very wise to keep up with the most update Java version for LW use (LW is written in Java & requires java for general functioning.) Java is not foolproof & still has some small probs. But these are being worked on which is why newer versions of java should be better.

Also keep your comp well maintained; ie: periodically run your disk & file utilities to make sure your HDD, files & directories are in a healthy state. Also to check there's no compatibility probs b/w any apps!