We have found a problem in the latest versions of pine..anything from pine4.10-3 on, (including the beta version pine4.21 fro redhat 6.2). The problem did not exist for pine4.10-1. The problem is that pine is very slow opening the inbox, or accessing the list of mail folders. In pine version 4.10-3, when we hit L, we get a busy message...sometimes for 20 seconds, until the folder list comes up. In pine version 4.21, we get a message saying "formatting scroll text" while pine is grinding away. This problem occurs only for systems for which the user home areas are on an nfs mounted volume. We have some systems which the home areas are local to the machine. There, everything works fine. So, I think the problem has to do with accessing folders on nfs mounted volumes. It could also be a network problem. comparing the source for pine4.10-1 and pine4.10-3, I noticed that the only differences were the extra patches pine-3.96-sigchld.patch pine-4.10-maildir.patch in 4.10-3 and pine4.10-quote.patch which was present in 4.10-1 but not 4.10-3. This latter looked inocuous, and pine-4.10-maildir.patch sounded like it might have something to do with accessing mail folders or directories.
Have you tried the pine shipping with 6.2? Could you just switch between the versions of pine to see if this really is the cause of the problem? (keeping netowrk configuration, kernel etc. the same)
After an e-mail discussion with the reporter and an upgrade of the system, the problem disappeared. I believe the problem to have been caused by NFS configuration.