Platform: Windows XP and Windows Vista (observed in both)
ISP: Clearwire
Type of Internet Connection: Wireless
Internet Connection Speed: up to 5Mbps
Date & Time: since last update
Frequency: often but intermittent
Character Name: Observed on both Larghaut and Marghaux
Race: ElvaanM and HumeF
World: Ragnarok
Main Job: several; generally RDM and PLD
Support Job: several, including SCH, BLM, DRK, WAR, DNC
Area and Coordinates: Observed so far in several Dynamis areas and in Bostauneaux Oubliette; probably worldwide.
Party or Solo: Doesn't matter.
NPC Name: Nauthima and Karyn
Monster Name: Doesn't matter.
Steps:
1. Use any spell/ability/item that adds Invisible effect.
EXPECT: Visual effect for Invisible (slightly-transparent character).
ACTUAL: Character remains visually "solid" ... sometimes.
2. If shown as invisible, change any visible piece of equipment (weapon, shield, or visible armor piece) that would cause the character to briefly disappear and be re-rendered.
EXPECT: Visual effect for Invisible remains intact.
ACTUAL: Character becomes visually "solid" ... sometimes.
3. If shown as invisible, cancel the effect by selecting it from the group of active effect icons.
EXPECT: Character becomes visually "solid".
ACTUAL: Character remains slightly transparent ... sometimes.
I have yet to observe a pattern of other factors that contribute to the bug. I have seen threads about this occurring on PS2 and XBOX as well, so it doesn't seem to be a technical issue (as was claimed in one of the other threads).
Further, I have observed that the visual effect for invisible allies has also been changed. Characters in your party or alliance who become invisible formerly disappeared completely; they will now turn partly-transparent (as if they're you) or will remain solid (as if they're you, bugged).