informix doesn't close connection; isql hangs on exit

Hi, We recently moved to a new sun machine running sol2.4. We run informix7.1. Applications and everything including isql run fine except that often when we exit from isql, it doesn't come back to shell. A similar thing happens with our application which runs the transaction fine but just doesn't return control to shell. I tracked it to the program line: EXEC SQL disconnect default where it hangs. This happens often but not always. A truss on the applic. shows that it waits on getmsg() form /dev/tcp and sleeps. Sometimes it returns in a few minutes sometimes won't. Here is the truss output: ...... snipped open("/dev/tcp", O_RDWR) = 6 ioctl(6, I_FIND, "timod") = 0 sigprocmask(SIG_BLOCK, 0xDFFFDC30, 0xDFFFDCE0) = 0 ioctl(6, I_PUSH, "timod") = 0 sigprocmask(SIG_SETMASK, 0xDFFFDCD0, 0xDFFFDCC0) = 0 ioctl(6, I_STR, 0xDFFFDAD8) = 0 sigprocmask(SIG_SETMASK, 0xDFFFDCC0, 0xDFFFDCA0) = 0 ioctl(6, I_FLUSH, FLUSHRW) = 0 sigprocmask(SIG_SETMASK, 0xDFFFDCE0, 0x00000000) = 0 sigprocmask(SIG_BLOCK, 0xDFFFDB60, 0xDFFFDCC0) = 0 ioctl(6, I_STR, 0xDFFFDC84) = 0 ........ snipped more ioctls read(0, 0x001626D4, 8192) = 0 write(6, "\\0 T\\0\\f", 4) = 4 getmsg(6, 0xDFFFEE1C, 0xDFFFEE10, 0xDFFFEE8C) = 0 write(6, "\\0 8", 2) = 2 getmsg(6, 0xDFFFEE7C, 0xDFFFEE70, 0xDFFFEEEC) = 0 putmsg(6, 0xDFFFEE00, 0x00000000, 0) = 0 ioctl(6, I_PEEK, 0xDFFFECC4) = 0 poll(0xDFFFEE38, 1, 100000) (sleeping...) and hangs at this poll() statement. If possible, please reply directly. Thanks much for any help. AH