I have been writing a program to use as a example for a group of kids I am coaching that may develop into a FLL team. Anyhow we are using the NXT-G software 2.0 that came with the kit. I wrote the program on some of my down time at work on a laptop with the software installed. Created the Pack and go. Then tried to open it on a laptop I am using for the group. Its a WinXP[MCE] machine that was fully formatted and restored using Restore CD's. All was well till now. The Pack and go program had broken My Blocks and some of the regular blocks looked white like they were not connected. At first I though maybe my .rbtx file was corrupt so I went upstairs to my Win7 pc with software installed and open it there. All was good....

Back to my Laptop I tried to make thing work there but each time I fixed a broken block or tried to rebuild the program NXT-G would Lock up or after saving, closing, then re-open more and new blocks and My Blocks broken.

OK Maybe the PC is corrupt. Try and format/restore? After all that still no dice. OK so scratch my rbtx file start everything from scratch..... Saving as I go..... Download/test/troubleshoot program on robot. I have a working program.... Come Back after supper....

fire up Laptop Broken blocks... Hacked away.. Started over again. I can now write it in under 30 min download/test program in robot all is working. Create Pack and go. Save Pack and go to USB drive. Close robot program not NXT-G software. Try and re-open. B R O K E N B L O C K S uggg

Go upstairs on Win7 PC Open Pack and go all is well

Frustrated Laptop would be nice to have working.
Take a look at the file if you feel it could be the root of the problem. I'm using many Variables and some nested MyBlocks.