I encounter this problem several times, the way to get around this is to give "Everyone or Network Service " permission to "C:\windows\temp" folder. I gave everyone on my development box just for convenient.

I hope it will help you solve the same problem as I had. 

Here are some references:

http://forums.asp.net/t/985047.aspx

"It is enough to give read, write permission to NETWORK SERVICE user. crystal report create a temp file with guid for name in windows temp folder, so it needs write permission to the disk to make create that temp file." 

http://aspadvice.com/blogs/rjdudley/archive/2005/03/15/2567.aspx