Hi Jeff,
The short answer is "no." It's not clear to me what the precise description of the problem the student is having really is, though. Is the sequence of events that the student enters answers, clicks "check answers" (or "submit answers") and then the graded page has none of the answers that the student entered? Is the student having trouble with the length of time that the server is taking to respond? Perhaps most importantly, is he entering, pressing preview, then pressing "back" and then pressing "check" or "grade"?
The other thing that may be worth trying is having the student come by and try to replicate the problem where you can watch to see what's going on. It's somewhere between very unlikely and certainly not a WeBWorK bug.
Gavin