Suspend problem when Quota Exceed

Hello
I think this is a bug in cPanel

cPanel Uses .htaccess to redirect disabled sites to suspended page.
When we suspend an account, if that account quota is exceeded, cPanel return error without any change in htaccess

Code:

Locking Password...Locking password for user username.
passwd: Success
Done
1Suspending email account logins for sitename.com .... Failed to write lock file: /home/username/etc/sitename.com/shadow.lock: Disk quota exceeded at /usr/local/cpanel/Cpanel/SafeFileLock.pm line 17.
[2013-12-13 15:29:53 +0430] warn [suspendacct] could not acquire a lock for '/home/username/etc/sitename.com/shadow' at /usr/local/cpanel/Cpanel/SafeFile.pm line 256
	Cpanel::SafeFile::_safe_open(GLOB(0x3f01c50), '<', '/home/username/etc/sitename.com/shadow', CODE(0x1eec370), 'safeopen') called at /usr/local/cpanel/Cpanel/SafeFile.pm line 32
	Cpanel::SafeFile::safeopen(GLOB(0x3f01c50), '<', '/home/username/etc/sitename.com/shadow') called at /usr/local/cpanel/scripts/suspendacct line 298
	scripts::suspendacct::_suspendshadowfile('/home/username/etc/sitename.com/shadow') called at /usr/local/cpanel/scripts/suspendacct line 291
	scripts::suspendacct::__ANON__(CODE(0x3f752a0)) called at /usr/local/cpanel/Cpanel/AccessIds.pm line 94
	Cpanel::AccessIds::__ANON__(CODE(0x3f752a0)) called at /usr/local/cpanel/Cpanel/AccessIds.pm line 134
	Cpanel::AccessIds::do_as_current_user(CODE(0x3f752a0)) called at /usr/local/cpanel/Cpanel/AccessIds.pm line 97
	Cpanel::AccessIds::do_as_user_group('username', 782, CODE(0x3f747f0), 'username', CODE(0x3f747f0)) called at /usr/local/cpanel/Cpanel/AccessIds.pm line 67
	Cpanel::AccessIds::do_as_user('username', CODE(0x3f747f0)) called at /usr/local/cpanel/scripts/suspendacct line 291
	scripts::suspendacct::suspendshadowfile('username', '/home/username/etc/sitename.com/shadow') called at /usr/local/cpanel/scripts/suspendacct line 145
	scripts::suspendacct::run('username', 'Suspended as one of reseller mobinho1’s accounts') called at /usr/local/cpanel/scripts/suspendacct line 34
Failed to read /home/username/etc/sitename.com/shadow: Disk quota exceeded at /usr/local/cpanel/scripts/suspendacct line 306.