[Vitaly]

Hmm... some additional mod conflicts? Don see any errors in my logs.

Try to edit global_start hook in this mod.

Change

if ($vbulletin->options['rcd_pm_log_show_link'] 
    AND (   THIS_SCRIPT == 'misc' 
         OR THIS_SCRIPT == 'member' 
         OR THIS_SCRIPT == 'showthread' 
         OR THIS_SCRIPT == 'rcd_pm_log'))

for

if ($vbulletin->options['rcd_pm_log_show_link'] )

Or just for

if (true)

if doesn't helps.